Abstract: Reduced graphene oxide(RGO) modified carbon fiber/polyphenylene sulfide composites (RGO-CF/PPS) were prepared by powder lamination methodand hot pressing process. Interlaminar shear properties and micromorphology of the RGO-CF/PPS composites at room temperature and hygrothermal environment were investi-gated. Meanwhile, the effect of RGO on the interface performance of the composites was analyzed. Results show that the interlaminar shear strength (ILSS) of the 0.1%RGO-CF/PPS composites in the dry state at room tempera-ture is 18.4% higher than that of the CF/PPS composites. After hygrothermal treatment, the ILSS of the RGO-CF/PPS composites are decreased and the ILSS strength retention rate of the RGO-CF/PPS composites is lower than that of the CF/PPS composites. Dynamic thermomechanical behavior results of the composites show that the RGO is helpful to enhance the interface bonding performance of the RGO-CF/PPS composites. Micromorphology shows that the RGO effectively improves the ILSS of the RGO-CF/PPS composites in the dry state at room temperature.