In this study, 480 on-day-old Arbor Acres broiler chicks were used in a 2*3 factorial arrangment with 2 levels of hull-less barley (0.30%)and 3 levels of enzyme (0.300 and 600g/ton), to investigate the effect of diets containing high soluble non-starch polysaccharides (NSPs) concentrations on morphological characteristics of small intestine and performance of broilers. Increasing in concentration of soluble NSPs significantly decreased feed intake and body weight gains of broilers,(p<0.05) height and width of villi and tongue shaped villi percentage but increased other types of villi and crypt depth in small intestine (p<0.01), Enzyme supplmentation of diets had no significant effects on studied traits, results show increase in the concentration of soluble NSPs of diet causes negative effects on morphological characteristics of small intestine in broiler chicks. Therefore, it could reduce absorption surface in digestive tract, and consequently decrease broiler performance.