Interval-valued intuitionistic trapezoidal fuzzy number is investigated. Some operational laws of interval-valued
intuitionistic trapezoidal fuzzy numbers are defined and some related properties are researched, the weighted arithmetic
average operator and weighted geometric average operator for the interval-valued intuitionistic trapezoidal fuzzy numbers
are given. The score function and accurate function of intuitionistic trapezoidal fuzzy numbers are defined, and then an
approach for ranking interval-valued intuitionistic trapezoidal fuzzy numbers is presented. The model of multi-attribute
decision making is constructed based on interval-valued intuitionistic trapezoidal fuzzy numbers. The corresponding method
of decision making is proposed. The example analysis shows the effectiveness of the method.