Abstract: In this study, the population dynamics of Acetes chinensis and major environmental factors were analyzed using data obtained in the early, middle and late months in the western Daya Bay from December 2016 to February 2017 and from December 2017 to March 2018. The results showed that the average density of A. chinensis differed insignificantly among transects L2，L3 and L1 while they were slightly higher than those from the transects L4 and L5. Besides, the density reached the maximum in January and February. There was little significant correlation between the density and temperature indicating that there was no evidence of temperature aggregation. It suggests that the dense phytoplankton population, particularly diatoms, encourage the growth because of food avalable. From December to February, A. chinensis body size turns larger from small and medium sizes. Thus, the larger individuals are more likely dominating the populations with decreasing temperature since the growth of A. chinensis and the algal blooms in the coldest season provided plenty food for the rapid growth of larger A. chinensis.