Seasonal variations in biochemical composition of the clam Dosinia corrugate were investigated from August 2013 until July 2014 in Zhuanghe Bay in relation to environmental conditions and reproductive cycle. Separate biochemical analyses of the mantle, adductor muscle, foot, and gonad-visceral mass in each sex were undertaken. Spawning took place once a year from July to August and the massive spawning occurred in August with the highest water temperature and chlorophyll a levels. Utilization of glycogen took place during the spawning period, whereas protein was biosynthesized as the mature gametes formed. The glycogen value increased during the resting stage (autumn—winter). The reproductive pattern exhibited by D. corrugate based on the storage of reserves during the period of sexual rest, and the period of gonad maturation, seems to be conservative and opportunistic. The information obtained in this study provides a basis for fisheries resource administrators to design biologically sound management measures for this species, and is crucial for initiating its aquaculture.