Through denoting each expert as an agent and viewing a multiple criteria decision-making as a synthesis problem of aggregating experts’ ratings, a multi-agent blind model (MABM) is developed for regional eco- environmental quality assessment. In this model, the ratings of the evaluated object under an index, given by expert group, are first utilized to construct a series of blind numbers. In general, each index will correspond to different blind numbers. On the basis of aggregating index weights, the rank score in the form of a blind number is obtained for the evaluated object. Then, by means of calculating expected value of the above blind number, its rank score is further converted into a crisp value. By way of comparing the expected value with classification standards, eco-environmental quality of the evaluated sample could be identified successfully in the end. As a case, the MABM is used to evaluate the eco-environmental quality of Chaohu Lake basin. Study result shows that the MABM is a useful model for regional eco-environmental quality assessment. Through denoting each expert as an agent and viewing a multiple criteria decision-making as a synthesis problem of aggregating experts’ ratings, a multi-agent blind model (MABM) is developed for regional eco-environmental quality assessment. of the evaluated object under an index, given by expert group, are first utilized to construct a series of blind numbers. On the basis of aggregating index weights, the rank score in the form of a blind number is obtained for the evaluated object. Then, by means of calculating expected value of the above blind number, its rank score is further converted into a crisp value. By way of comparing the expected value with classification standards, eco-environmental quality of the evaluated sample could be identified successfully in the end. As a case, the MABM is used to evaluate the eco-environmental quality of Chaohu Lake basin. MABM is a useful model for regional eco-environmental quality assessment.