We studied with respect to changes in chlorophyll content and chlorophyll retention of leaf segments accroding to the growth of various leaf blades in rice plant. The results obtained may be summarized as follows : (1) Leaf blades can be classified into two groups in patterns of changes in chlorophyll content of leaves, namely, the first group of leaves grown in vegetative stage and the second group of leaves grown in reproductive stage. The first group of leaves showed higher chlorophyll content and shorter living day of leaves than that of the second group of leaves. (2) Except for reduction division stage and heading stage, the chlorophyll a/b ratio of various leaves was about three through the growth stage. Remarkable increase of the chlorophyll a/b ratio was seen at reduction division stage and just after heading stage. (3) There was high significant correlation between the chlorophyll content and the nitrogen content. The first group of leaves showed an increase in chlorophyll content with a decrease of nitrogen content according to growth. (4) Changes in chlorophyll retention of leaf segments of the first group of leaves differed from that of the second group of leaves. The former's chlorophyll retention declined rapidly as growth advanced, but the latter's declined slowly showing a oscillation.