Abstract: The distribution,speciation and molecular weight distribution of cadmium(Cd) in the Pteria penguin tissues and organs were studied by graphite furnace atomic absorption spectrometry and gel filtration chromatography technology. The results showed that the contents of Cd in the various tissues and organs of the Pteria penguin were 2.33 mg/kg the whole viscera,2.50 mg/kg mantle,2.40 mg/kg adductor muscle,2.38 mg/kg visceral mass,2.24 mg/kg foot,1.42 mg/kg gill. 83.3% of the full shell Cd accumulation in visceral mass,adductor muscle and mantle in Pteria penguin. Less than 40% of the Cd in different tissues and organs of the Pteria penguin bound in the form of water soluble protein. Two ultraviolet absorption peaks of proteins,which had a relative molecular weight of more than 26000 u and less than 16000 u,were got after the isolation of soluble thermally stable protein of water soluble protein from every organ by Sephadex G-50 gel filtration column chromatography. The Cd in visceral mass,mantle and gill were distributed in two molecular weight proteins. About 90% Cd in adductor was distributed in nonprotein compounds while a small quantity of it was combined with proteins of high molecular weight. Nearly all the Cd of soluble thermally stable protein in foot were combined with proteins of high molecular weight. This research revealed that distribution and molecular weight distribution of Cd in the Pteria penguin tissues and organs differences.