Abstract: The sample of arsenic filter cake was treated with a mixture of HNO3 and H2O2 by microwave digestion, and rhenium in the sample solution was determined by ICP-MS. 185Re was selected as the isotope for measurement, 193Ir was used as internal standard. Linearity range of rhenium was found within 50 μg·L-1, with detection limit (3s) of 0.037 μg·L-1. Recovery and precision of the method were tested by standard addition method, giving values of recovery and RSD′s (n=11) in the ranges of 96.0%-102% and 2.0%-3.8% respectively.