Abstract: According to the requirements and indexes of the Evaluation Method of Aquatic Biological Integrity Index in the Yangtze River Basin，the base value of aquatic biological integrity evaluation in the Qinghai region of the Changjiang River Basin was first clarified.We conducted comprehensive fieldwork to detect the aquatic biodiversity in the Qinghai region in the Changjiang River basin in 2022.The results indicated that the base value of the fish species number was 20，and the current fish species number was 19.The aquatic biological integrity scores of the source reach of the Qinghai region in Changjiang River，the source reaches of Dadu River，and the whole Qinghai region in the Changjiang River basin was 88.22，82.67，and 81.56 points，respectively，and all of the integrity levels were “good”.Among them，15 species of fish ever recorded in the Changjiang River source were all found in this survey，reflecting that the aquatic community in the Changjiang River Source Basin was less disturbed by human beings，and the key protected species were intact.The fish habitat in the study area was good，the main factors restricting the integrity were the barrier of hydropower stations to the river，the invasion of exotic species，and the loss of the key species of hucho bleekeri.The research results can provide basic data for the comprehensive evaluation of the water ecological integrity of the Qinghai region in the Changjiang River，and can also provide a scientific basis for the scientific evaluation of the effectiveness of the 10-year fishing ban in the Changjiang River and the targeted ecological restoration of the waters.