TChlorophyll fluorescence parameters of 1 to 5 fully extend leaves in maize seedlings grown under different light conditions were investigated in order to study the photochemical activity of maize leaves at different positions.The results showed that the variation tendency of fluorescence parameters of leaves at different position of maize seedlings under different light intensities was different.Fo of leaves at all leaf positions were higher when light intensity was 200 μmol.m-2.s-1,but were lower when light intensity was 200 μmol.m-2.s-1.Fv/Fm of the first leaf was the highest when light intensity was 200 μmol.m-2.s-1.Fv/Fm of the fourth leaf and fifth leaf was higher than of the first,second,and third leaves when light intensity was 600 μmol.m-2.s-1and 1000μmol.m-2.s-1.The proportion of the energy absorbed and captured by the second and the third leaf but used for heat dissipation increased when light intensity was 1000 μmol.m-2.s-1,while that of the fourth and fifth leaf at leaf 2 and 3 under 1000μmol/(m2.s) light condition,but that of leaf 4 and 5 increased when light intensity was 1 300 μmol.m-2.s-1.It meant that the photochemical activity of fourth and fifth leaf was higher than that of the former 3 leaves when light intensity was 600 and 1 000μmol.m-2.s-1.