Abstract: The comprehensive assessment of observed behavior of earth-rockfill dams was a complex analytical problem.The analysis and assessment of safety of earth-rockfill dams was just being researched,and the monitoring model and assessment theory were not mature.Combining the engineering characteristics of earth-rockfill dams,a comprehensive assessment system for behavior of earth-rockfill dams was established,which consisted of three main parts as follows: the method of setting a comprehensive assessment index system,the means of measuring assessment index,and the way of making the comprehensive assessment.Moreover,the comprehensive assessment method for behavior of earth-rockfill dam was established in a multi-pole fuzzy pattern on the basis of applying the theory of engineering fuzzy sets.It was shown with an example that the model was reasonable and reliable.