Abstract: Based on characteristics of the eco-environment in the middle reaches of the Heihe River and PSP model,9 evaluation index systems that reflect eco-environmental frangibility while being isolated from each other were selected to form a model for integrated evaluation of eco-environment fragility of the studied area using the matter-elements theory and information entropy.Results indicate that Minle and Ganzhou Counties were the least,Jiayuguan city was medium,Suzhou,Gaotai and Lingze Counties were slightly high,and Shandan County was the highest in eco-environmental fragility.Sensibility of evaluation factors varied from factor to factor and from county to county.The evaluation results obtained using such a model are basically consistent with the local conditions.