Seven different fertilizer samples were selected for digestion by nitric acid-hydrochloric acid(aquaregia). The contents of heavy metals such asarsenic(As)，cadmium(Cd)，lead(Pb)andchromium(Cr)in the digestion solution were determined by helium collision mode using an inductively coupled plasma massspectrometer(ICP -MS)method. The resultsshowed that:based on the solid weight of 0.2 g and the constant volume of 50mL，the detection limits of Cr，As， Cd and Pb were0.018，0.008，0.005 and 0.021mg/kg，respectively，and the limits of quantification were0.061，0.025，0.016 and 0.069mg/kg，respectively. According to the liquid weight of 1.0 g and the constant volume of 50mL，the detectionlimits ofCr，As，Cd and Pb were0.004，0.002，0.001 and 0.004mg/kg，respectively，and the limits of quantification were0.012，0.005，0.003and 0.014 mg/kg，respectively. The relative standard deviationof Cr，As，Cdand Pb( n=6)were 3.8%-16.8%，3.9%-56.5%，0-25.7% and 4.2%-24.5%，respectively. The recoveries were 67.4%-122.0%. Samples of different fertilizer types wereextracted from four laboratories for laboratorycomparison，and the analysis showed that there was consistency between the test values of all the participating laboratories. After the outliers were removed by the Cochran test and the outliers wereretained，the Grubbs test wasapplied to the unit average after passing the Cochrantest，and no single or pairs of outliers or outliers were found for each element. The precision and accuracy of the method meet the requirements. Conclusion suggested that ICP-MS could be used for the determination ofAs，Cd，Pb and Cr in fertilizer.