In this research, we propose the gradual-priority weighting (GPW) approach to search the Pareto optimal solutions for the multi-objective flowshop scheduling problem. The proposed approach will search feasible solution space from the first objective at the beginning and towards the other objectives step by step. To verify the effectiveness and efficiency of our proposed approach, GPW will be compared with the variable weight approach. Through the extensive experimental tests, the proposed method performs quite effectively and efficiently.