More carbohydrates such as reducing sugars, non-reducing sugars and crude starch in leaves were accumulated in NH_4-N fed plants than in NO_3-N fed plants. The amount of reducing sugars accumulated in NH_4-N fed plants was about twice as much as in NO_3-N fed plants. More reducing and non-reducing sugars were also accumulated in roots of NH_4-N fed plants than in those of NO_3-N fed plants, and more reducing sugars in roots were accumulated between 8 a. m. and noon in NH_4-N fed plants than in NO_3-N fed ones. Invertase activity in leaves was higher in NH_4-N fed plants than in NO_3-N fed plants. It was consequently presumed that the increase of invertase activity had a close relation to the accumulation or reducing sugars in NH_4-N fed plants. It was also presumed that HMP shunt is playing greater part in the course of glucose metabolism in NH_4-N fed plants than EMP pathway, judging from the result of experiment of feeding with glucose-1-^<14>C and glucose-6-^<14>C.