Abstract: Fish play an important role in maintaining the stability of river ecosystems. Seasonal changes affect fish community structure to a certain extent. In order to understand the structure and seasonal differences of functional groups of fish in Jinan City, 40 samples from the waters of Jinan City were selected in spring (May), summer (August) and autumn (November) in 2014 for the fish communities. The physicochemical factors of the water and environment were analyzed by means of one-way analysis of variance, multi-response replacement process, and canonical correspondence analysis to analyze the differences of fish functional groups in different seasons. The results showed that:(1) A total of 26 species of fish were identified in spring, including 5 orders and 7 families; 32 species were identified in summer, including 5 orders and 9 families; 20 species were identified in autumn, including 5 orders 7 families. The fish is divided into four subgroups of four functional groups in terms of habitat layer, spawning type, tolerance to the environment, and nutrition structure. In spring, the main functional groups were herbivorous, bottom layer and sensitive species. In summer, the main functional groups were carnivorous, lower middle level, antifouling, special spawning and viscous egg functional groups. In autumn, the main omnivorous and buoyant egg groups were upper middle layer and antifouling functional groups dominant. (2) Canonical correspondence results showed that:the driving factor that affects the distribution of sticky egg functional groups, carnivorous functional groups, underlying functional groups, and the distribution of sensitive functional groups is dissolved oxygen; the electrical conductivity is the driving factor that affects the herbivorous functional group. Seasonal changes in fish functional groups occurred by combined endogenous and exogenous combined effects, which means the combined effects of seasonal change on living habits and environmental factors.