Objective To identify autophagy-related genes (Atg) in fall armyworm (Spodoptera frugiperda) genome and their response to viral infection in S. frugiperda, and provide a basis for further research on the molecular mechanism of autophagy.Method Autophagy-related protein (ATG) sequences from various species, such as human (Homo sapiens) and fruit fly (Drosophila melanogaster), were aligned and analyzed for sequence similarity. ATG sequences in S. frugiperda genome were searched. Conservative domain (CD) of the candidate ATG were analyzed by NCBI CD search. Furthermore, qRT-PCR was used to detect the expression changes of Atgs in Sf9 cells after infection by recombinant EGFP-AcMNPV.Result We identified more than ten core Atgs which were involved in autophagosome formation in S. frugiperda, including the complete sequences of Atg3, Atg5, Atg6, Atg7, Atg10, Atg12, Atg13 and Atg101, and the partial sequences of Atg1, Atg2, Atg4, Atg9, Atg14, Atg16, Atg17 and Atg18. The expression levels of S. frugiperda Atg2, Atg4, Atg5, Atg6, Atg7, Atg8 and Atg12 were up-regulated after 6 to 12 hours infection by EGFP-AcMNPV.Conclusion Eukaryotic conserved Atgs exist in the genome of S. frugiperda, indicating the autophagy pathway in S. frugiperda is evolutionarily conserved. AcMNPV infection might trigger the autophagic response in Sf9 cells.