[Objectives]  To clarify the population biotype of invasive Spodoptera frugiperda in Ganzhou, Jiangxi province in order to better understand the occurrence and spread of this important, global agricultural pest. [Methods]  Molecular identification of 32 S. frugiperda specimens collected in Ganzhou, Jiangxi province was based on variation in the COⅠ and Tpi molecular markers. DNA was extracted from each specimen, amplified with PCR and sequenced using COⅠ and Tpi molecular markers, after which the COⅠ and Tpi gene fragment sequences obtained were analyzed. [Results]  Gene fragments of the expected fragment size were obtained from all 32 samples. The length of the COⅠ gene fragment was 713-779 bp, and that of Tpi gene fragment was 383-395 bp. Based on previous analysis of the CO I gene, the corn strain of S. frugiperda accounted for 62.5% of specimens and the rice strain for 37.5%. However, on the basis of Tpi gene variation, all specimens were of the corn-strain, of which there were three types (Tpi-Ca1, Tpi-Ca2 and hybrid Tpi-Ca1/Ca2).A phylogenetic tree ofCOⅠ gene variation indicates that S. frugiperda COⅠ sequences in Ganzhou, Jiangxi province are consistent with those elsewhere in China (Jiangsu, Yunnan and Jiangxi), in the United States (Puerto Rico and Florida), in Africa (Uganda), but differ from those in Brazil. [Conclusin]  This study clarifies the genetics of S. frugiperda in Ganzhou, Jiangxi province, thereby increasing the available information on the population genetics of this important global pest.