Abstract: To solve the problem that the present risk assessment method of tailings dam does not consider the correlation between monitoring indexes resulting in double calculation during the evaluation process，the correlation between the monitoring indexes is considered and converted them into weights，so that the dominant index had the smaller weight，and vice versa.So the problem of double counting can be lowered.An integrated weighting method was used to determine the weights:according to the characteristics that monitoring indexes has different influence on each other，an influencing matrix is established.As the experts information required in the matrix is fuzzy，the trapezoidal fuzzy number is used to describe experts information and to calculate the subjective weights；With features of fuzziness and randomness，the monitoring data are represented by possibility distributions，then the correlation coefficient weighting method was used to calculate the objective weight of every index；Subjective weight and objective weight are integrated by the mean method.Example results show that:the weight calculation method that considers the coefficient of monitoring indexes can reduce duplication in risk assessment，and integrate subjective and objective weights.This method provides the theoretical basis for weighting of each index for tailings dam.

Key words: Tailings dam, Risk assessment, Correlation, Influence matrix, Possibility of correlation coefficient weighting method