Abstract: To solve the problem of lacking suitable variable rate fertilizer spreader in China, a variable rate fertilizer spreader with conveyor chain based on prescription map was designed. A motional equation of fertilizer granular at the moment of thrown from disc border was established through analyzing force and motion of fertilizer granular at spreader disc, and then the system of key components was designed and the corresponding machinery parameters were confirmed, such as variable rate control system, fertilizer box, the auto-opening device of gate etc. The experiments on different fertilizer amount and uniformity were conducted with a variable rate fertilizer spreader. Results showed that the spreader′s effect of variable rate fertilization and uniformity of the spreader was better. When the speed of tractor was 1.5 m/s, relative error between actual application amount and pre-setting amount was less than 7.53%. When the speed of tractor was 2 m/s, the coefficient of variance was 14.90%, fertilization amount was 225 kg/hm2 and the spreader breadth was 30 m, which indicates the spreader can meet the need of practical production.