Agriculture on Earth has developed at several areas in various ecosystems during long periods after the end of the final glaciation by replacing natural producers with crops and by making human as a sole cousumer mainly through the method of trial and error. On the contrary, agriculture on Mars should be created rapidly and unmistakably under natural conditions completely different from those on Earth. In addition, the agriculture on Mars should supply clean water and air as well as foods necessary for sustaining the emigrants to Mars. This can be achieved by a strategy consisting of two stages. The first stage is to modify the air, water, and debris inside an artificial dome somewhat similar to those on Earth. The second stage is to establish a sustainable agriculture on Mars. These two stages are discussed rather in detail.