The objective of these experiments gas to investigate the feeding of Powerfeel supplementation on performance and intestinal microflora of broiler chicks. Five treatments were allocated into 0, 0.025, 0.050, 0.075, 0.10% Powerfeel with four replications for five weeks. Diets contained 21.5% CP, 3,100 kcal/kg ME for the first three weeks and 19% CP, 3,100 kcal/kg ME for the rest two weeks. Weight gain, feed intake, feed conversion were weekly measured. E. coli and Salmonella were examined from cecum and ileum at the end of experiment. ND titer were also measured at five weeks old after first and booster vaccination at 14 and 21 days of age. In experiment 1, Weight gain of Powerfeef treatments was significantly higher for five weeks (P〈0.05). Feed intake increased on all Powerfeel treatments. Chicks fed Powerfeel improved feed conversion ratio(FCR) significantly compared to that of control (P〈0.05), but was not shown the consistency. In experiment 2, Weight gain and feed consumption of chicks fed Powerfeel were tended to increase, but were not statistically different from control. Powerfeel treatments showed significantly lower FCR than control(P〈0.05). The number of Salmonella and E. coli of chicks ileum fed Powerfeel were highly decreased, compared to those of control in both experiments. Powerfeel supplementation seemed to decrease the number of both Salmonella and E. coli in illeum, but was not consistency in cecum. Chicks fed Powerfeel showed significantly higher ND titer than control (P〈0.05). These results indicated that the optimum level of Powerfeel to maximize the performance of broiler chicks were estimated from 0.050 to 0.075% in broiler diets.