In order to determine the hydrocarbon accumulation period of Permian volcanic reservoirs in western Sichuan basin, petrographic analysis of fluid inclusions, fluorescence microanalysis, homogenization temperature measurement were conducted to solve this problem.The results show that the main host minerals of the inclusions are quartz and calcite filled in the pores, and the inclusions are distributed in bands or groups. The hydrocarbon inclusions are relatively mature and appear blue and white under fluorescence. The homogenization temperature of inclusions showed unimodal characteristics, and the peaks was 110℃~130℃. Combined with the analysis of the burial and thermal evolution history of the study area, the Permian volcanic reservoirs in the western Sichuan basin have experienced hydrocarbon accumulation periods, the period occurred in the Early Triassic (245~243Ma present), which is the main hydrocarbon charging period.