Considering the detoxication functions of Glutathione S-transferase (GST) enzyme, that is important against oxidative stress, cancer and others degenerative diseases, this study aimed to evaluate the stability and activity of Glutathione S-transferase extracted from bovine liver, which is commercially available at low cost. The extraction was done in four steps (homogenization/centrifugation, passage through column containing diethylaminoethyl-cellulose (DEAE), precipitation with ammonium sulfate and passing through column of carboxy-methyl-cellulose (CMC). The extract thus obtained showed activity with 1 chloro 2, 4 dinitrobenzene, in the presence of reduced glutation. The specific activity of the final extract was 5 times greater than the crude centrifuged extract, and was stable for 70 days when stored at 5 degrees C.