Abstract:Effects of water temperature, nitrogen, phosphorus, vitamin and antibiotic on the growth of toxic Alexandrium tamarense (Hong Kong strainⅡ) were studied under experimental conditions. Optimum growthtemperature, N and P concentrations were 21-25℃, 882-1 765 μmol/L and 18-72 μmol/L, respectively. Complex vitamin B was found to be beneficial for the algae growth, whereas over 50 U ml-1 antibiotic showed obviousinhibition effect.