To understand the current status of fish resources in Lake Bosten and their relationship with environmental factors， a lake-wide acoustic survey was conducted in May （spring）， July-August （summer）， and October （autumn） of 2019 using a split-beam echosounder （Simrad EY60， 120 kHz）， along with on-site measurements of aquatic environmental indicators. The results showed that fish density in Lake Bosten was the highest in summer， with an average value of （8 783±2 611） ind./hm². There was no significant difference between spring and autumn， with the average values of （709±141） and （743±499） ind./hm²， respectively. Based on the empirical formula between target strength and body length， the average total length of fish in spring， summer， and autumn was estimated to be 8.8， 4.0， and 5.1 cm， respectively. Correlation analysis indicated that the fish density in Lake Bosten was significantly positively correlated with water temperature and electrical conductivity （P<0.01）， but significantly negatively correlated with transparency （P<0.05）. The feature importance ranking of the random forest model revealed that electrical conductivity was the most important factor influencing fish density in Lake Bosten， followed by dissolved oxygen， salinity， and water temperature. Seasonal variation in fish density is presumed to be closely related to environmental changes， food sources， and reproductive habits. Environmental factors may directly or indirectly affect the ecological and environments needs of fish.