Product variant design is one of the key technologies of Manufacturing Enterprise for responding market demand. During the product variant design, tolerance variant design plays an important role. However, tolerance variant design is considered rarely in the researches of product variant design. To solve the problem of tolerance design in product variant design, a component variant design method integrating dimension and tolerance is presented in this paper. The fundamental and implement of component dimension variant design is introduced. Through analyze the conventional tolerance design method; the status for tolerance variant with its implemental dimension is marked as fixed tolerance value, fixed tolerance grade and tolerance value variant with special regular. The equation of dimensional tolerance variants with the value of implemental dimension is presented. So the procedure of component variant design method integrating dimension and tolerance is proposed. Finally, a case study of output shaft of reducer illustrates the implemental process of proposed method. Result comparing with conventional method shows effectiveness of proposed method.