The modern study of the Meng Jiangnü tale begins with the birth in the 1920s of China's folk song studies (geyaoxue) and folkloric studies (minsuxue) movements. These had their origins in the late-Qing period, but the documentation of China's folkloric traditions was undertaken as a part of an agenda of national heritage (guogu) studies. Prominent among the early folklorists were pioneers of what were called the New Culture and the Vernacular Literature movements, among whom the most significant figures were Hu Shi, Liu Fu, Zhou Zuoren, Zhong Jingwen and Gu Jiegang. Although these scholars were elitist in their cultural outlook, they were convinced of the primacy of popular and vernacular culture within the overall development of Chinese literature and culture. Their preoccupation with folklore echoed 19th century European developments associated with the rise of nationalism.
In the study of the Meng Jiangnü legend, Gu Jiegang (1893-1980) is the leading figure, and his published studies were described by folklorist Zhong Jingwen as 'The Analects of folkloric research'. Gu Jiegang is best remembered as one of the creators of a new school of historiography that sceptically examined the textual layering in the written accounts of ancient history. Central to his examination of the role of folklore within history and the broader culture was his extensive research on the legend of Meng Jiangnü. This went back to the winter of 1922 when he took up a teaching position in Peking University's Department of Guoxue ('National Studies' or Sinology). In the winter of 1923, he published his seminal paper 'Meng Jiangnü gushi de zhuanbian' (The transformation of the story of Meng Jiangnü), and in 1924 Geyao zhoukan (Folksong review) commissioned him to prepare a further paper treating issues associated with the transformation of the legend of Meng Jiangnü. Yet he had not anticipated the wealth of data into which he was tapping; he had only reached the 10th century in his researches when he had already written some 12,000 characters in length. As a result, he had to be content with publishing only the first part of his study in the 69th issue of Folksong review which came off the presses on 23 November 1924 as a special issue devoted to the Meng Jiangnü legend. The article attracted great attention as soon as it appeared, and letters commending the pioneering folkloric work of Gu inundated the journal. Readers from across China also informed the scholar of variants of the Meng Jiangnü legend in various local prose, drama and folk song forms. From Paris, Liu Fu, one of the prime movers of the May Fourth New Culture movement, provided Gu with the texts of the Meng Jiangnü legend that appeared in manuscripts of vernacular literature discovered in the Library Cave at Dunhuang by Paul Pelliot. This unexpected support encouraged Gu to research Meng Jiangnü literature even more fully. In conformity with research as it was then conducted internationally, he isolated mythic themes or universals within the legend as well as particularities of detail, and then outlined a major investigative project with twenty-four topics that examined aspects of the legend through the process of transmission. These topics encompassed the geographical spread of the story, and the particular contours the legend acquired around sites related to the Great Wall, such as the passes at Shanhaiguan and Tongguan, and the northern counties of Tongguan, Xushui and Fengzhou, as well as the unique features the legend assumed in southern China – in Guangdong, Guangxi, Jiangsu and Zhejiang provinces - far from the Great Wall.
The wide range of topics he set out to explore included the origins of the custom of presenting padded clothing (hanyi), and the expressed belief in the power of lamentation that can topple an unnatural monument. He also examined exegetically the name of Meng Jiangnü against the background of complex practices of female naming in the Warring States. He would eventually show that Meng Jiangnü was a portmanteau term in the Warring States period for a woman of great beauty.  In all, Folksong review published nine issues devoted to Meng Jiangnü, presenting not only Gu's writings but an extensive correspondence and articles on the subject by a number of other scholars and aficionados of folklorica, often with commentary by Gu. This constituted a preliminary round of collective research.
A second round of research was initiated by Gu in June 1925. In this second period he no longer simply examined myths and legends in terms of their themes and elements from a historical perspective, but turned to investigate ancient history in light of what the transformations in legends revealed about history itself. Gu Jiegang now treated the Meng Jiangnü legends as an archaeological artefact, and Gu's excavation of the text was a decoding of what the transformations in legends signalled about the societies that gave rise to them. For Gu, Meng Jiangnü now had validity less as mythology than as multi-layered sets of ultimately historical texts; his excavation of the embedded structure of the legend in historical texts ultimately became a study of the underlying structure of ancient society itself as viewed through the accretions in bodies of legend.
In 1926 Gu succinctly explained his scholarly approach: 'There are two tasks I wish to undertake: one is to use the outlook of stories (narrative) to explain the elements that structure ancient history, and the other is to provide a systematic account of ancient and modern myths and legends'.  From documenting changes in mythology, he turned to examine why mythology changed.
Meng Jiangnü is a legend which has developed and changed almost beyond recognition. Most modern variants of the folk tale incorporate some of the following elements and themes: the power of passionate mourning to subvert or destroy the man-made order; the tyranny of Qin Shihuang; the Great Wall; the agony of separation; virtuous chastity; unrequited love; and, unparalleled beauty that has the power to devastate.
Unlike many legends, Meng Jiangnü harks back to named historical personages and historical tales. Most scholars follow Gu Jiegang in believing the original Meng Jiangnü to be the wife of the Ji Liang mentioned in a passage in the pre-Qin history Zuo zhuan relating events of the 23rd year of the rule of Duke Xiang, and that the name Ji Liang transformed later into Fan Xiliang, the name of Meng Jiangnü's husband in the modern version of the legend. The brief passage in Zuo zhuan records that after Ji Liang's death in battle, his widow could not accept that the Marquis of Qi had held the mourning ceremony for her husband outside the city walls, a form of commemorative service called the 'suburban mourning' (jiaodiao), and thereby only accorded her the respect due to a concubine, not a wife. Neither the Great Wall nor Qin Shihuang nor Meng Jiangnü appears or is named in this seminal glimpse of the legend. Subsequently, in the text of Tangong, a work of the Warring States period, contained in the ritual text Xiaodai Liji, there is a passage which describes how Ji Liang's wife 'received his coffin by the roadside where she wept piteously'.
Lamentation forms the core of the early legend and it is that theme which has enabled researchers to trace the origins of the tale. In the 'Gaozi, xia' section of Mencius, the ability of Ji Liang's wife to weep for her husband 'changed the customs of the nation'. However, even at this time, the legend was not fully formed because the other important element, the 'collapsing walls', had not yet appeared. Gu Jiegang suggested that it was in the Han dynasty, following the articulation by Ying Shao and other philosophers of the theory of the interaction of heaven and man that elements documenting the impact of Meng Jiangnü's lamentations on the natural (mountains) and man-made order (walls) appeared. In some early versions, the mourning of Meng Jiangnü is to have 'toppled the mountain' (bengshan).
In two works of the Western Han dynasty and Wei-Jin period, Liu Xiang's Shuo yuan and Lienü zhuan, we begin to find the connection between the mourning for the husband of Ji Liang and the collapse of walls. Later, in the Tang dynasty story Tongxian ji (found in the anthology Diaoyu ji [Carving jade]), Meng's daughter marries a farmer called Ji Liang who has taken refuge on the Meng family estate to avoid being conscripted for hard labour on the Great Wall. After Ji Liang's death on the Great Wall, Meng Jiangnü's 'lamentations toppled the ramparts' (kudao changcheng). Meng Jiangnü's name also appears in a Dunhuang ballad (quzici), underscoring the fact that the fully formed legend had emerged by the Tang dynasty.