Abstract. The aim of this paper is to develop a novel approach for multiple attributes group decision making, in which the decision information, provided by multiple decision makers, is presented in the form of interval-valued intuitionistic fuzzy numbers. First, the aggregated information matrix corresponding to all decision makers is calculated with the weights of both attributes and decision makers, the aggregated matrix is obtained. Then, a new biparametric similarity measure is used to computed the similarity between the alternatives and the positive ideal point and negative point via the idea of the TOPSIS of Hwang and Yoon (1981), the optimal choice is computed to choose the alternatives which perform best, an illustrative example is presented to demonstrate its effectiveness and validness of the proposed approach.