Different supplementary enzymes have used widely in diets for ruminants and non-ruminants over the past decade. The present study investigated the effects of feeding natuzyme (enzyme supplement) on feedlot performance, feed digestibility and rumen metabolites of Varamini male lambs. Twenty-four Varamini male lambs (initial body weight 22±1.5Kg with 3 to 4 months age) used in a completely randomized design for 84 days. The lambs were randomly allocated to three rations of 1) without enzyme, control diet, 2) with 0.5 g/kg of feed natuzyme, 3) with 1 g/kg of feed natuzyme with 8 replication. Basal diet was formulated according to CNCPS for sheep. Daily dry matter intake and monthly average gain of lambs recorded and digestibility of basal diet measured with chromic oxide as external marker. At the end of examination, rumen liquid samples collected from lambs and its pH and ammonia nitrogen were measured. The results showed that diets did not make significant effect on the average daily gain, dry matter intake and feed conversion ratio in lambs. Meanwhile, digestibility of crude protein, ether extract, dry matter, organic matter, neutral detergent fiber and acid detergent fiber of basal diet, ruminal pH and ammonia nitrogen did not show difference between diets. We concluded that use of 0.5 or 1 g/kg of feed natuzyme did not make significant effect on the performance of Varamini male lambs.