Abstract: A Method is presented for ultra-trace rare earth elements analysis in biological samples using inductively coupled plasma mass spectrometry. By using well-tested method and appropriate sample preparation procedures,hair,serum,blood and tissues samples can be analyzed with good accuracy and precision. The detection limits are in the order of 7 to 26 pg/mL. The recovery for spiking GBW 09101 hair sample is 95% to 105%, relative standard deviation (RSD) is 2.6% to 4.2%.