Hitherto, in interpreting the fluctuation of water soluble protein extracted from rice kernel in ripening stage, fresh rice kernel has been used. Dried rice kernel capable of germination was used in the present work. The authors believe that such consideration for material is important for the study of the quality of rice kernel. In this paper, rice kernel with ripening was investigated on changes of physical and chemical characters. The results obtained are summarized as follows :
1 . The decrease of both crude-ash and ether-extract content (%) was shown with ripening but the increase was recognized in absolut content (mg) in a kernel. The content of ether extract in the variety named "Norin No. 17" was richer than "Aichi-asahi".
2 . Rice kernels by means of alkali test (2.4 % KOH, 25℃, 24 hrs.) were resistant to disintegrate in later ripening.
3 . Nine amino acids from rice kernel were observed in any time of ripening, while content of aspartic acid and histidine went on increasing with the progress of ripening.
4 . The difference between fresh and dried materil for 3-weeks duration after flowering was always observed on paper electro phoretic pattern of water soluble protein from rice kernel. Four bands on the patterns were founded in the material in later ripening as previously reported.
There were 2 fractions of water soluble protein in embryo part of kernel and with ripening, the bands of these fractions were more clearly shown on electrophoretic patterns.