The effect of subcutaneous administration of carbon tetrachloride to rats on the quantitative and qualitative changes of glycosaminoglycans, i.e., hyaluronic acid (HA), chondroitin sulfates (CS) and dermatan sulfate (DS), in the liver, kidney, spleen, plasma and urine was investigated. In the cases of the liver, kidney and plasma, no difference was found in the amount of glycosaminoglycans between carbon tetrachloride-treated rats and normal ones. On the other hand, all of the glycosaminoglycans examined in this study (HA, CS and DS) increased considerably in the spleen and urine after the repeated carbon tetrachloride administrations.