As the second report on studies of nitrogen nutrition for muskmelon, this report deals with the results of experiment to clarify the influence of increased phosphoric concentration in nutrient solution upon the growth of melon and the absorption and assimilation of two forms of nitrogen, NH_4-N and NO_3-N, in the tissue of it. The results obtained can be summarized as follows. 1. Metabolism in the melons of AP-series was not only activated to some extent but also their growth was promoted by the increased phosphoric concentration in nutrient solution. However, even when the phosphoric concentration was raised up to 100 ppm, the growth of the melons of AP-series was recognized to be far less than that of NP-series. 2. Since the amount as well as the content of absorption of bases such as K, Ca and Mg in the melons of AP-series were much lower than those of NP-series, the base content in total together with the absorption of the former was also only about half of those of the latter. This fact indicates that those melons of AP-series absorbed NH_4^+ and at the same time, the absorption of mineral nutrients may be more affected remarkably by the form of nitrogen than by the concentration of phosphorus in nutrient solution. 3. Since water soluble organic nitrogen and its ratio to total nitrogen, of AP-series except AP_0 plot, were much more and higher than those of NP-series, and on the contrary, the ratio of insoluble organic nitrogen to total nitrogen was comparatively low, it can be presumable that there were somewhat of disturbance in the synthesis of protein in the melons of AP-series. This disturbance, however the phosphorus concentration be raised up, could not completely be removed from the melons of AP-series. 4. The same thing above is clearly certified in the metabolism of carbohydrates. The high content of each sugar and crude starch in the melons of AP-series showed that the metabolic activity was disturbed and that it was impossible to remove the retardation of growth of the melon fed with NH_4-N, however high phosphorus concentration be supplied. 5. From the analytical results of free amino acids and amides, glutamic acid was recognized to be accumulated to excess in the tissue of the melons of nonphosphorus plots. This may presumably be attributed to the fact that such phosphoric components in the melon as pyridoxal phosphate, the coenzyme of transamination, ATP concerning synthesis of glutamine, lowered their supplying capacity as a result of phosphoric deficiency.