Abstract: The study on the effect of lanthanum-proline and lanthanum-phenylalanine complexes on Chaetoceros mulleri showed that these two complexes could distinctly enhance its cell reproduction and chlorophyll synthesis.When the concentrations of lanthanum-proline and lanthanum-phenylalanine was 1～15mg·L^-1,the cell numbers on the sixth day were increased by 13.2～19.2% and 12.6～21.5%,and the concentrations of chlorophyll by 25.2～33.9% and 26.2～45.1%,respectively(P<0.05), with an optimum concentration of 5 mg·L^-1 .The effect of lanthanum-proline and lanthanum-phenylalanine on C.mulleri was the same as that of lanthanum, but their optimum concentrations were reduced obviously.

Key words: Lanthanum-proline, Lanthanum-phenylalanine, Complex, Chaetoceros mulleri, Enhancement effect