These studies were undertaken to determine the $CO^2$fixation patterns following the chloroplast development in maize leaves. At the early stage of chloroplast development $^{14}C$ was incorporated into aspartate (41%) and malate (22%) respectively. Whereas the incorporation of $^{14}C$ into malate was higher than that of aspartate as chloroplast developed. Activity of NADPH-dependent malate dehydrogenase was increased throughout chloroplast development, but that of aspartate transaminase was not. Much incorporation of $^{14}C$ into aspartate at the early stage of chloroplast development and into malate at later stage of chloroplast development lead us to conclude that NADPH-dependent malate dehydrogenase activity is closely associated with chloroplast development, but activity of aspartate transaminase is not.