Abstract: Important effect of chitosan on regulating plant growth , eliciting plant resistance to disease and it’s possible operating mechanism are reviewed . Chitosan shows evidence physiological effect on the key enzymes of ammonia assimilation and enhances the amination capacity in plant, which is in favor of biology synthesize and accumulation of protein . Thus , chitosan improves nutrition quality and horticulture properties of plant . Moreover , chitosan rapidly stimulates plant defense responses , then startups defensive system and elevates resistance to disease . To a further understanding of the mechanism of chitosan on plant , we have isolated and determined some biochemical properties of a chitosan-bingding protein .

Key words: Chitosan