Abstract:The chlorophyll protien complexes separated from several plants were resolved by SDS-PAGE. It showed that the percentage (18%) of complex Ⅳ in total amount of chlorophyll of castor bean (Ricinus communis L.) was obviously higher than that ( 13% ) of snake gourd (Luffa cylindrka (L.) Roem) and the percentage (41%) of LHCP complex in total amount of chlorophyll of castor bean was lower than that (48%) of snake gourd. The light-induced variable fluorescence change of castor bean (Fv/Fo=2.6) was much higher than that of snake gourd (Fv/Fo = 1.08) and other plants. The photochemical activities of chloroplasts of castor bean were very high. Its oxygen evolution activity (H20 → DMBQ) was 575 μ moles O2·mg-1Chl·h-1, and the oxygen absorbtion activity of PSⅠ (DCIPH2 → WV) was 1274μ moles O2·mg-1Chl·h-1, the Chl/P700 ratio was 373, but those of snake gourd were 210, 148 and 751 respectively. There were distinct difference between the polypeptide pattern of castor bean and those of other plants. It was observed that 43, 47 KD polypeptide bands (polypeptides of PSⅡ) of castor bean were darker than those of other plants. From the results mentioned above, it was considered that the high photochemical activities possessed by castor bean chloroplasts were partly due to its small photosynthetic units, e.g. its LHCP/RCCHL ratio yas smaller than those of other plants.