The purpose of this study was to investigate the metallothionein of acute cadmium poisoning mice as a Cadmium index. Forty male ICR mice were injected with cadmium chloride solution from 1/8LD50 to 1/2LD50 dose. At 24 hours after exposed Cd, I examined Cd and metallothionein (MT) intissues (liver and kidney ) and fluids ( whole blood and urine) and also measured low molecular proteins, N-acetyl- -D-glucosaminidase ( NAG ) and 2microglobuline ( 2-MG ) in urine. The concentration of Cd and MT of liver, kidney whole blood and urine were increased with dose dependent manner. Urinary Cd and urinary MT had very good significance ( p< 0.01) and urinary MT had good significance with kidney Cd and NAG but not 2-MG. Conclusionally MT in urine was very correlated with kidney Cd and urine Cd. So MT maybe useful as a Cd poisoning index.