Two experiments were conducted to study the effect of adding soy-lecithin or xylanase to low-energy diet on broilers growth performance, nutrient digestibility, intestinal lipase enzyme activity and economical efficiency. A total number of 256 unsexed Cobb500 broiler chicks, a day old, were classified into two equal experiments, 128 chicks each (4 treatments × 4 replicates × 8chicks). In each experiment, chicks were divided into 4 groups as follows: - the 1st group fed basal diet and served as control which fed recommended energy diet, the 2nd group fed diet low (100 Kcal / kg diet) than recommendation (LED), the 3rd and 4th groups were fed 2nd diet added with 0.5g lecithin / kg diet or 1.0g lecithin / kg diet, respectively (EXP.1). While, chicks were fed 2nd diet supplemented with 0.1g xylanase / kg diet or 0.2g xylanase / kg diet, respectively (EXP.2). The growth trail was lasted at 35 days of age. The results revealed that, groups of LED + 0.5g lecithin (EXP.1) and LED + 0.2g xylanase (EXP.2) recorded significantly higher BWG and better FCR during overall period than control and LED groups. In both experiments, there is a gradual increase in EE% digestibility coefficient, intestinal lipase activity and economical efficiency by increasing the addition level of either soy-lecithin or xylanase. It could be concluded that enriching low-energy diet with either 0.5g lecithin / kg diet or 0.2g xylanase / kg diet can improve broilers growth performance, intestinal lipase activity and enhanced economical net profit.