Species diversity, richness and evenness of fishes from Are-laung-wei-tode Lake were recorded during January to December 2015. A total numbers of 45 species and 70890 individuals were recorded. The highest diversity (0.1121) in September and the lowest (0.2312) in April were recorded. Regarding the highest evenness value (0.6495) was found in December. The lowest evenness value (0.4396) was found in July. Relative results of the diversity indices evaluated during the study periods, indicated that (d), (D), (H'), (N1) and (N2) were high, either in the month of September, which fall in the mid rainy season, during which fresh stock of fish were replenished by the inflow of water from the main river. On the seasonal basis, the lowest diversity values were recorded in hot season and the highest values were recorded in rainy season. This research was indicated the ecosystem of Study Lake is healthy and habitat is stable.