Abstract: The chromium speciation in the liver cytosol fraction,serum and urine of both normal and diabetic rats are studied by the enriched stable isotope tracer technique combined with the gel chromatography and the neutron activation analysis (NAA).The results are as follows: (1) When Cr(Ⅲ) enters the animal body,it is most likely to be combined with serum proteins.The chromium protein compound acts as a carrier to transport Cr to the whole body.In the liver cytosol froction,Cr(Ⅲ) is also mainly combined with the high molecular weight protein and retains as chromium protein substance in the liver. (2) A low molecular weight chromium containing compound is found in all the liver cell cytosol fraction,serum and urine of the two group rats. (3) The diabetic rats lose more amount of low molecular weight of chromium compound in urine than the normal rats do.This might be a main reason to explain why the diabetic rats retain lower Cr in their bodies than the normal group.