Garlic (Allium sativum) is a biennial herb of the family Liliaceae. It contains various active components like allicin and its derivatives S-allyl cysteine, diallyldisulfide, diallyltrisulfide which increase the sulfhydryl groups available to form soluble complexes with lead and pairing the essential sulfidryl groups of enzymes and protein thereby preventing more internal toxicity. In this experiment, one 162 mature male rats (250 gr on the average) were acquired from Razi Serum – producing Institute of Karaj-Iran and transferred to keeping place. This design is performed as a factorial experiment 3*3 (3 level of Garlic Aqueous Extract (GAE) extract and 3 level of Chromium Chloride (CrCl3) supplement) in the form of totally random design with 9 groups per 3 replications each containing 6 rats. At the end of fourth week, after 12 hours starvation, six rats per treatment were selected randomly from every treatment and their blood sampling was collected for biochemical traits, then serum concentration of creatinine, urea and uric acid were determined. It revealed that garlic aqueous extract results in decrease urea and creatinine and increase in uric acid but these changes were not significant. Also, CrCl3 supplementation as single use yields to decrease urea and uric acid (P>0.05) and increase creatinine (P<0.05). Data showed that combinative use of garlic and CrCl3 supplementation yields to decrease in urea when garlic was 60 mg/kg and CrCl3 was 4 mg/kg also when garlic was 120 mg/kg and CrCl3 was 4 mg/kg but this decrease was not significant (P>0.05). Combinative use of garlic and CrCl3 supplementation yields to increase in creatinine values in all doses and uric acid when garlic was 60 mg/kg and CrCl3 was 4 mg/kg (P≤0.05).