Abstract: Considering the fuzziness of the evaluation criteria in product shape design,operational techniques of intelligent design are discussed.Based on the product shape coding,the paper discusses a method for reducing solution space dimensions by evaluating parameters’weights with the help of the weight concentrating curves.An interactive genetic algorithm is used in the downsized solution space for seeking optimal solutions.Then,the product shape details are determined gradually.The method extracts the parameters’weightiness from user interactive selection information,and takes it as the base for evolve the shape design from concepts to details.The solving process is thoroughly based on decoded product shapes,which helps designers select design solutions conveniently.