This study aimed to investigate the effects of prebiotic, probiotic, and synbiotic supplementation on the performance, small Intestinal morphometry, and carcass traits of broiler chicken. A 160 one-day-old Cobb 500 broiler chicken was used and arranged as a completely randomized design of 4 treatment groups with 4 replicates of 10 chicken each. Supplementation was through drinking water along the experiment (28 d): P0=control, P1= prebiotic inulin, P2= commercial probiotic and P3= synbiotic mix prebiotic + probiotic and used according to the dosage of prebiotic and probiotic. One brand of commercial feed was provided, and consisted of three rearing phases was used throughout the study, and as such drinking water was provided unlimited. The parameters measured are daily feed, water intakes and weight gain. The digestibility, Gross morphometric indices of small intestine are measures of the length/weight ratio of individual segment, duodenum, jejunum and ileum and carcass traits were measured at the end day of the experiment on 3 chicken samples (lightest, average, and heaviest) of each treatment unit. The research parameters, namely feed and water intake, weight gain, feed conversion ratio, performance index, digestibility on crude protein intake, crude protein in feces, crude fiber in feces, crude protein and crude fiber, small intestine morphometry the length/weight ratio of individual segment, duodenum, jejunum and ileum and carcass traits are indicated as carcass percentage and carcass density. The effects of prebiotic, probiotic or synbiotic supplementations on parameters feed and water intake, weight gain, feed conversion ratio, performance index, digestibility, small intestine morphometry and Carcass traits were significantly affected on synbiotic supplementation compared to prebiotic, probiotic and control. The responses of body weight gain and feed conversion ratio are also indicated as the Performance Index of the supplementation synbiotic, and the synbiotic chicken group appeared a better improve performance compared to the other groups. In conclusion, synbiotic supplementation showed a better beneficial synergistic supplementation compared with those of prebiotic or probiotic supplementation separately on production performance, feed utilization efficiency, carcass traits and index performance of broiler chicken and synbiotic can significantly reduce feed use as assessed by feed conversion.\r\nKeywords: Broiler chicken, natural growth promotors supplementation, performance index, small intestinal morphometry, carcass traits.\r\n