Abstract: The influences of three instrumental parameters of ICP-MS spectrometer(radio frequencey power, nebulization gas flowrate and ion lens voltage) on signal intensity and productivity of a few kinds of ions formed from 15 rare earth elements in the plasma(single element ions RE⁺, oxide ions REO⁺, hydroxide ions REOH⁺ and hydride ions REH⁺) have been investigated. The relationship betWeen the productivity rate of these ions and properties of relevant RE element has been explored. The results use for selecting instrumental parameters for determination of 14 trace rare earth impurities in high-purity single rare earth samples by ICPMS.