Abstract: A method of ICP-MS for the determination of trace amount of cadmium in zirconium alloy with CCT was proposed. Oxygen was used as reactant gas for collision to eliminate the interference of polyatomic ion ZrOH with determination of Cd. Linear relationship between values of peak area and mass concentration of cadmium was kept in the range within 5.0 μg·L-1, with detection limit (3σ) of 0.122 μg·L-1. Precision was tested with 0.5 μg·L-1 of Cd(Ⅱ), value of RSD (n=11) found was 2.8%.