The main aim of the present study was to determine the in vitro effect of some heavy metals in general and copper in particular on the activity of sheep liver glutathione-stransferases (GSTs). Besides that, the in vitro effect of camel whey on copper inactivated GSTs was also studied in this research. The effect of heavy metals zinc, nickel, cobalt, manganese, copper and camel whey on GSTs activity was studied by spectrophotometric method using 1-chloro-2,4-dinitro-benzene (CDNB) as substrate. Results showed that copper ion had the most potent inhibitory effect on GSTs activity when compared to other studied heavy metals as it directly reduced the enzyme residual activity to reach 29.3% at 2 mM concentration. In addition to that, the further increase in incubation time between heavy metals and GSTs lead to an increase in inhibitory behavior of all heavy metals under study. Furthermore, the role of camel whey on copper inactivated GSTs was clearly showed that it can reduced the inhibitory effect of copper on enzyme activity prior to its addition. The acquired residual activity after direct whey addition increased from 0.76% to 16.48% at 2 mM copper concentration. Moreover, the pre-incubation of GSTs with camel whey for a certain period caused better effect than its direct addition. Hence, the residual activity of GSTs increased from approximately zero to 38.5% at 2 mM. In conclusion, camel whey play an important role in the activation of copper inactivated GSTs.