Objective To establish an ICP-MS method for the determination of 16 rare earth elements in grains.Methods Samples were digested by microwave oven.The operation parameters of the instrument were optimized.Kinds and dosages of internal standard elements were tested and analytical performances were estimated.Results The contents of 16 rare earth elements in grains were determined.Relative standard deviations were in the range of 0.2%-2.1%.The recoveries were in the range of 90.5%-109.0%.Detection limits were less than 0.007 ng/ml.Conclusion The method is accurate,sensitive,rapid and simple,and accorded with the demands of trace analyzing.