Abstract: Drosophila melanogaster is an established model to study innate immune responses and host-virus interactions. RNA interference（RNAi） is one of the main antiviral mechanisms of Drosophila. Drosophila C virus（DCV） is a positive-sense RNA virus which is a natural pathogen of Drosophila, it encodes a viral suppressor of RNAi（VSR） DCV1A to counteract the RNAi pathway. In this study, a total of 108 proteins were identified in Drosophila S2 cells that may interact with DCV1A by co-immunoprecipitation（Co-IP） and mass spectrometry. Then the interaction between DCV1A and TM2 was validated by Co-IP and Western blot to identify the interacting protein TM2 of DCV1A.The expression level of Tm2 was increased in S2 cells infected with DCV; When DCV1A and Tm2 genes were co-expressed in S2 cells, the level of DCV1A protein was significantly down-regulated, then DCV replication was also suppressed in the co-transfected cells. Both Tm2 mutant and wild-type fruit flies were intrathoracically injected with DCV and the survival rates were monitored daily. The results showed that Tm2 mutant flies were more susceptible to DCV infection than wild-type fruit flies. Taking together, the results presented in the study demonstrated that Tm2 inhibited DCV replication in both S2 cells and adult fruit flies.