Abstract: A new process was proposed for extracting cadmium from cadmium-containing raw materials by the ammonium-ammonia method.Investigation on leaching in the process for treating an electric precipitation dust from ISP sintering factory was carried out.The best conditions were established as follows:the ratio of liquid to solid was 2.5,［NH₃］/［NH₄⁺］=3/5,total concentration of ammonium and ammonia was 8 mol•L^-1,the leaching time was 1.5 h at 35℃.Under the above conditions, leaching rate of cadmium and its concentration in the leached solution was 90.99% and 8.74 g•L-1,respectively.