A method was developed for seawater analysis by inductively coupled plasma-mass spectrometry. To a seawater sample with 1 mg Fe, 2 ml 1% ammonium pyrrolidinedithiocarbamate was added at pH 2 or pH 4 for coprecipitation of Co, Ni, Cu, Nb, Mo, Cd, Sn, In, Te, and Pb or Be, Sc, Ti, Cr, V, Co, Ni, Cu, Zn, Ga, Ge, As, Zr, Nb, Sn, In, Te, rare earth elements, Hf, Ta, W, Tl, Pb, Bi, and Th. The procedural recovery and reproducibility are ∼96% and ∼4.4%, respectively. This method was validated with seawater references, and the results were consistent with their certified values.