| In order to explore the spatial and temporal variations of algal functional groups in the Zipingpu reservoir, a typical channel-type reservoir in the southwest mountainous area of China, water samples were collected from eight sections of the Zipingpu reservoir from April 2016 to March 2017.A total of 21 algal functional groups were identified as B, C, D, F, G, H1, J, L0, LM, MP, N, P, S2, T, W1, W2, X1, X2, X3, Y, and Z. Based on the analysis of the dominant degree (y > 0.02), the algal functional groups were dominated by W2, Y, L0, W1, MP, and B. The C-R-S strategy of algal growth in the Zipingpu reservoir showed that R-type was a more dominant type than the S- and C-type for the majority of the time. Peridinium (group L0, type S) was the significant algae in the Zipingpu reservoir algal bloom event in June 2016.Redundancy analysis (RDA) was used to explore the relationship between algal functional groups and environmental factors. The results showed that algal density, chlorophyll a, water temperature, and biochemical oxygen demand were the major factors influencing the spatiotemporal succession of algal functional groups across the eight sampling sections, with water temperature having the highest influence.