Abstract: In this paper, a multi-objective optimization model that combines the minimization of make span and environmental impact of wastes is proposed for multiproduct batch chemical process scheduling. In this model, environmental impact factors for various wastes and a decision factor are defined for trading off between make span and environmental impact of wastes. An improved SA (Simulated Annealing) algorithm is adopted for solving the problem,and several cases for an example problem are studied.The results show that the proposed model can be used to reflect how the environmental impact consideration affects the scheduling of a multiproduct batch process.