Abstract: In this paper, conditions in the determination method of Cu, Pb, Zn, Cd in sea water were optimized, the effects of rinsing solvent, extraction solvent, chelating agent, pH, and uptake rate on the determiantion results were studied. Under optimized conditions, the relative standard deviations(RSDs) of Cu, Pb, Zn, Cd are in the range of 0.0%~2.0%. The determination results of standard samples are better than that of GB17378.4-2007, ICP-AES and Polarographic methods.