To better understand the annually structural changes and succession rules of algal communities, the algal communities was analyzed in Zhalong wetland, which involved the dominant algal group, niched width, MFG (Morpho-Functional Groups), niched overlap and connection coefficient. Results showed that the total of 311 species from 8 phyla were identified. The algal species richness was the highest in summer, and its dominant species in the whole year were Chlorella stenostis and Cryptophyllum rodentuma. The species and density of dominant species varied with spring (Chlorophyta sp. and Chrysophyta sp.), summer (Chlorophyta sp. and Cryptophyta sp.), and autumn (Cryptophyta sp. and Chlorophyta sp.), indicating that the water environments exhibited the seasonal fluctuation. The dominant algal species were divided into three large niche groups judged by niche width and MFG functional groups. The seasonal variation of dominant algal species reflected the fluctuation of wetland water environment, from "nutrient-poor shallow water type" in spring to "nutrient-poor mixed water type" in summer and "nutrient-neutral still water type" in autumn. The wide niche algal species in each season reflected the seasonal variations and could be used as ecological indicators for reflecting the Zhalong wetland water environments changes. The niched overlap values could reflect the competition between dominant species in different seasons, with the proportion of O_ik>0.6 was 42.86% (spring), 28.57% (summer) and 25.00% (autumn), respectively. The resource competition among dominant species was the most prominent in spring, with the species of Chrysospora sp. dominating. In summer, it reached a relatively stable state, with the dominant species such as Chlorophyta sp. dominating, and the competition of Cryptophyta sp. intensified in autumn.Interspecific association tests showed that the overall interspecific associated algae were positively correlated, but the algae in Zhalong wetland was relatively less. The results of variance ratio method showed that VR values were all greater than 1, indicating that there was a positive correlation between dominant species of algae communities under independent null hypothesis. Statistical W-value test results showed that the overall association of dominant algal species in Zhalong wetland was not significant in the three season, indicating that the overall association of dominant algal species in Zhalong wetland was loose and tended to be random, and the community structure was unstable due to the great influence of external disturbance on community stability. Based on the Chi-square test results of 18 dominant species throughout the year, only 4 pairs of 171 interspecific pairs were extremely significant positive associations, while the other pairs were not significant, which also indicated that the composition stability of dominant species in Zhalong wetland was poor, and the results of Jaccard index also confirmed this conclusion. The analysis indicated that the niched algal communities in Zhalong wetland exhibited obviously seasonal fluctuations, and could be adopted as the ecological indictors for reflecting the water environment variation in the wetland.