From March 2013 to February 2014,the gill net and cages were conducted on the fish resources in 8 sampling sites of Lake Taihu, aiming to understand the characteristics of Acheilognathinae community structure and diversity in the lake. A total of 50 fish species were collected, belonging to 23 families,and 8 orders, among which, Acheilognathinae,Gobioninae and Engrauulidae had the larger species number and had an obvious tendency of fish resources becoming smaller-scale; as compared with historical data, 57 fish species were not collected,the fish species number and composition of dominant species changed greatly. A total of 7 Acheilognathinae species were collected, belonging to 2 families, the Acheilognathus chankaensis and Acheilognathus macropterus were the main species and allometric growth,other fish were isometric growth.The cluster analysis showed the significant differences in spatial and temporal aspects among the Acheilognathinae in Lake Taihu, clustered into two groups according to the time,from May to December for a group, and the index of N%、W% and IRI showed dominant species was Acheilognathus chankaensis,other time was Acheilognathus macropterus; clustered into two groups according to the space,the Manshan and Gonghu for a group and dominant species was Acheilognathus chankaensis, and other station was Acheilognathus chankaensis.It showed that the diversity index was below the average(1.5-3.5).They were closely related between spatial and temporal variations of fish and distribution patterns of nutrients, environmental factors, plankton, and aquatic plants in the lake.