Abstract: Photosynthetic characteristics,light-response curve and fluorescence kinetic parameters were measured for the yellow green maize of Zea mays L.and two normal inbred maize lines Mo17 and RP128 by a portable photosynthetic analyzer LI-6400 and Pulse-Amplitude-Modulation Chlorophyll Fluorometer.Results showed that the net photosynthetic rate(P_n),stomatal conductance(G_s)and intercellular CO₂ concentration(C_i)for yellow green maize yglm1 were significantly lower than the normal inbred lines Mo17 and RP128,but the transpiration rate(T_r)was significantly higher.The photosynthesis-light response curve indicated that light compensation point,light saturation point,dark respiration rate and apparent quantum efficiency for yellow green maize were higher than normal inbred lines Mo17 and RP128.Measurement of fluorescence kinetics parameters showed that initial fluorescence(F_o),maximal fluorescence(F_m),primary light energy conversion of PSⅡ(F_v/F_m),efficiency of light energy capture by PSⅡ(F_v'/F_m'),actually photochemical efficiency of PSⅡ with light(Φ_PSⅡ),and photochemical quenching coefficient(qP)for yellow green maize were significantly lower than normal inbred lines Mo17 and RP128,but non-photochemical quenching coefficient(qN)was significantly higher.Yellow green maize had lower photosynthetic rate than Mo17 and RP128,which may be related to their lower electron transfer potential,lower light capture efficiency and transformation efficiency,and lower energy allocation and utilization.