The relations between rate of growth and accumulation of carbohydrate on the Cryptomeria seedlings have attempted to explain the mechanism of nitrogen metabolism through and qualitative investigations of assimilation process on absorbed different nutrition by roots. Starch, reducing sugar and nonreducing sugar were estimated about whole samples taken once two weeks. The content of carbohydrate generally decreases in the vigorous time of the height growth, and on the contrary, increases in the time of thickening growth. There is in agreement with the view, that was a little change on the amount of nonreducing sugar and growth from the passage. of year. Another point of interest appeared on the physiological nutrition of Cryptomeria japonica as remarkable circulation of change on the reducing sugars, it is a different manuring or not. Then the dressing of nitrogen rapidly reduces the content of carbohydrate in the Cryptomeria seedling, and after some intervals again rearises to the degree far higher than before.