Abstract:  The service function of water retention is central in the ecosystem service function. The quantitative evaluation of water retention function can provide reference for the evaluation of regional ecological environment quality. Based on InVEST model with localized parameters analyzed the temporal and spatial changes of water retention year by year from 2000 to 2019 in Anhui Province and the differences of influencing factors under different climatic conditions. The results showed that in the past 20 years, Anhui Province water retention service function has enhanced. The spatial distribution pattern of water retention depth is high in the south and low in the north. The depth of water retention in the Qiantang River Basin is greater than that in the Yangtze River Basin, and the depth of water retention in HuaiHe River Basin is the lowest. The average annual water yield depth of Anhui Province was 763.1mm, the average annual water yield was 10.65×1010 m³, the average annual water retention depth was 193.7mm, the total amount was 26.8×109 m³. From the land types, grassland water yield capacity was the strongest, woodland water retention capacity was the strongest. In the dry years of 2001, normal years of 2008, and wet years of 2015, there was no significant difference in the q ranking of the explanatory strength of the water retention function among all factors, and the intervention intensity of human activities on the water retention service function was constantly increasing.