Aimed at several typical phytoplankton in East China Sea which belongs to Bacilariophyta or Pyrrophyta respectively, the effects of nitrate and phosphate on the growth and nitrate reductase activity of the phytoplankton was conducted with the batch culture experiment in the laboratory in this thesis in the base of the optimization of Cell-free method which was used to measure the nitrate reductase activity(NRA) in marine phytoplankton qualitatively and quantitatively. The nitrate and phosphate concen...