Abstract: The chlorophyll contents in individual leaf blades were studied from 1980 to 1982.The main results are described here in this paper.The chlorophyll contents(a+b,a/b)differed markedly among leaf blades.The change of the contents in the first leaf blade showed a short,early,and acute mono-peaked curve,while the contents in other leaf blades showed double-or poly-peaked curves.In general,the higher the leaf,the later the peak of chlorophyll contents would appear except the last leaf,During the whole growth period,the chlorophyll contents in the leaf blades showed five peaks,i.e.from the emergence of the second leaf to that of the third leaf,from tassel apex elongation to vertical section formation,from floret formation to tetrad formation,from tassel emergence to silking,and from the beginning of the filling stage to its peak period.This trend changed with dry matter content in leaf blades.

Key words: Summer maize, Chlorophyll content