We evaluated the extent of glycation of hair protein (keratin) using a glycation index (A390/A412) that was calculated from colorations (A412, cystine A390, glycated protein) of hair that can be quickly obtained by a non invasive procedure and easily stored. The glycation indexes of back hairs from hypercholesterolemic mice with hyperglycemia and diabetic rats were significantly higher 2.3-3.1 fold) than those of normal animals (p<0.05). Their glycation indexes correlated well with levels of glycated protein in hairs (r=0.98, p<0.05) and blood glucose levels (r=0.73, p<0.05). Within run precision (reproducibility, CV) for the assay of glycation index of hair was 6.7-9.4%(n=10). In conclusion, the proposed glycation index for hair gave reasonable results in animals with normo and hyperglycemia, indicating it to be reliable and diagnostically useful.