Abstract:Photosynthetic properties of thylakoid membrane of Anabaena azollae Strasb. were characterized as followed: ( 1 ) Photosynthetic O2-evolution of the thylakoid cells were meas~ when various culture fluids were used as reaction media. It was fotmd that induction of the photosynthetic O2-evolution was delayed by NH4CI and the rate of that was inhibited by both NH4Cl and DCMU (an electron transport-inhibitor). (2) The absorption spectra of A. azollae cells in the range of 700 ~ 300 nm exhibited four higher peaks at 680, 625,480 and 440 nm. Among which the peak of 625 nm must be an essential absorption peak of blue-green azollae. (3) The cell walls of A. azollae cells can be broken by Yada and sonication through which the thylakoid membranes were isolated. The preparation of membranes showed the abilities of cyclic photophosphorylation and the activity of membrane-bound ATPase. (4) ATPase were isolated and partially purified from the thylakoid membrane. The pattern of SDS-PAGE showed that molecular weights of the δ and ε subunits in the AT-Pase from A. azollae thylakoid membrane were less than the molecular weights of δ and ε subunits in the ATPase from thylakoid membrane of spinach chloroplasts. However, the molecular weights of α and β subunits in these two ATPase preparations were similar.