Male Wistar rats were procured from 'The Bombay Veterinary College', Parel, Mumbai. The animals were maintained and housed in cages and were acclimatized in laboratory conditions for ten days prior to the experiment. The experimental rats were fed orally with isoniazid 300 mg/ 70 kg body weight / day; rifampicin 450 mg / 70 kg body weight / day and Aloe vera extract 50 mg/ kg body weight / day for 30 days. Blood samples of the above groups (A to H) were taken after 30th day from cardiac puncture for estimation of mean concentration serum of AST, ALT, ALP, and ACP, bilirubin, total proein, total albumin and total globulin in serum of rats treated with Aloe vera, Isoniazid and Rifampicin independently as well as in combinations. In our study the more commonly measured 'liver' enzymes are showing significant increase in the levels of AST, ALT, ALP, and ACP, bilirubin total proein, total albumin and total globulin in serum of rats treated with Isoniazid and Rifampicin individually .