The Putative role of Calmodulin in regulating cell Proliferation and differentiation. Was tested in the Phototatic green alge Chiamydomonas reinhardii cells. The calmodulin levels of the cells was detected with a Calmodulin Enzyme-Linked Immunosorbert Assay (ELTSA) kit (provided by Xu Zhou Medical College and Nanjing Agrioulture University), and found that the amount of the Calmodulin in each cell was increased from early G_1 to S phase. Using three Calmodulin antagonists:TFP.CPZ and W_7. We recongnized they had an effect on the cell proliferation, and this results were achieved by using the technique of cell cycle kinetic analysis of Flow Cytometre (FCM) and by cell counters. The effects of the three drugs on Nitrate-deficient induced gametogenesis was also detected. The drugs had no effect on this process.