Abstract: A model of atmospheric monitoring siting with multi-objective programming was established in this paper. The model consists of three objectives and one constraint, and can be solved by using evaluation function method. The model was used to solve a monitoring siting programming of SO_2. The results show that the multi-objective programming of siting has some advantages, such as providing a series of siting projects, saving cost of siting, improving quality of siting and having a wider scope of application, compared with a single-objective optimization of siting with the same siting data.