Four types of magnetic alloy cores, labeled as V1, V2, A1 and A2, were produced by Liyuan Corp. Ltd., for the radio frequency compression cavity of HIRFL-CSRm. In this work, their permeability, quality factor (Q value) and shunt impedance were measured before installing them into the cavity. The results show that the V1, V2 and A2 have higher permeability and shunt impedance, and lower Q value, and are suitable to the radio frequency compression cavity.