Abstract:The chlorophyll-protein complexes of spinach and Chinese cabbage chloroplast thylakoid membranes could be resolved by SDS-PAGE into 8 and 7 chlorophyll-containing bands respectively. After treatment of Cu2+-Chelators such as bathocuproine and histidine, the experimental results indicated that the CPIa, CPI and LHCP2 bands of both plants were damaged, and the amount of LHCP3 band of them obviously increased. After treatment of Cu2+, the experimental results indicated that Cu2+ led to the loss of CPa1 band of spinach and CPa band of Chinese cabbage. Cu2+ could change the spectral properties of the CPI band of spinach that led to a shift of the red maxima absorption from 678 nm to 672 nm, and appeared a very weak shoulder at 652 nm, and also showed a fluorescence emission peak at 679 nm, so that it became similar to the property of LHC-Ⅱ. Cu2+ could change the spectral properties of LHCP1 and LHCP2 bands of both plants that led to a shift of the red maxima absorption from 672 nm to 668 nm or 69 nm, and led to the LHCP2 band show a main fluorescence emission peak at 724 nm, so that it is likely to close to the property of LHC-Ⅰ. Therefore, it is suggested that a possible role of Cu2+ is in regulating the energy distributionbetween reaction center and light-harvesting chlorophyll protein complexes and the light-harvesting chlorophyll protein complexes themselves by allosteric effect in both photosystems.