In order to test the regulation effect of carboxymethyl chitosan on rice nitrogen metabolism,Xiangwanxian 6 and Xiangwanxian 9 were used as samples.Under the treatment of carboxymethyl chitosan(concentration of 0.2% water solution),the nitrate reductase,glutamine transversase,gl-utamine synthetase and protease activities of top 3 rice leaves at the heading stage were increased obrionsly,and the enhancement on the activities of glutamine transversase and protease continues till the late .The amount of ...