[Aim]  To clarify the parasitoid species and parasitic status of the overwintering population of the rice stem borer (Chilo suppressalis) in Sichuan, thereby providing a foundation for the utilization of parasitoids as agents of biological control for this pest. [Methods]  Specimens of the overwintering population of C. suppressalis were collected from 6 sites in Sichuan from February to April each year between 2019 and 2023. Parasitoid species were identified by morphology and 28S rDNA sequences. The parasitism rate was also recorded. Adult longevity of parasitoids was determined using honey water as a food source. [Results]  Seven species of parasitoids of the overwintering population of C. suppressalis were identified, including Chelonus munakatae, Microgaster russata, Amyosoma chinensis, Cotesia flavipes, Eriborus terebrans, Auberteterus alternecoloratus and Trichomalopsis apanteloctena. Sequences of the 28S rDNA D2 region of 7 species were obtained. A phylogenetic tree based on 28S D2 variation indicates that every parasitoid clustered with species in the same family. Parasitism rates of the overwintering population for each year between 2019 and 2023 were 6.28%-11.78%, 0.81%-5.50%, 0.88%-14.34%, 2.34%-16.60% and 3.47%-18.07%. C. munakatae was the most common parasite followed by E. terebrans, C. flavipes and M. russata. These four species are widely distributed in Sichuan Province. Average lifespans of A. alternecoloratus, C. munakatae, E. terebrans, M. russata and C. flavipes were 18.20, 7.89, 6.10, 5.69 and 2.74 days, respectively. [Conclusion]  An abundance of parasitoids parasitize the overwintering population of C. suppressalis in rice fields of Sichuan. There is consequently considerable potential for using parasitoids to improve the management of C. suppressalis in Sichuan Province.