We examined 72 female Wistar rats which were divided into 6 groups. The animals were administered sodium nitrate (V), vitamin E or both compounds at the same time. In order to estimate the interference of nitrates in the presence of vitamin E with the metabolism of rat's liver, we determined the composition and the amount of glycosoaminoglycans (GAGs). It was stated that the total amount of GAGs increased in livers of all rats. Basing on all fractions of the examined GAGs it was determined that the most significant differences between individual groups appeared in the amount of heparane sulphate (HS). The results obtained confirmed the fact of the changes taking place in the picture of liver GAGs in the process of ageing of the examined animals. The results obtained, however, allowed to state the normalising influence of vitamin E on the quantitative composition of GAGs of rats which drank nitrates.