Abstract: Chitosan, a natural renewable resource of the earth, belongs to nonpoisonous and pollution-free security animal hormone substance. The important development of chitosan used as biopesticide was summarized in this paper. Chitosan plays very important roles in many aspects, especially the induction of plant disease resistance, the bioactivity as pesticide and germicide, plant resisting to adverse conditions, seed-coating, fruits and vegetables storage, insecticidal synergism, soil improvement, plastic film degrade, promoting growth, increasing yield and improving quality. these have been demonstrated in many crops including wheat, corn, rice, soybean, potato, cucumber, tomato, celery, green pepper, chinese cabbage, banana, mango, apple, pear and straw berry. Chitosan’s extensive applicative prospect in agriculture production was showed.