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Lighting schedule and nutrient density are both crucial elements for broiler production.They can affect broiler performance and welfare, which can be indicated from their behavior rhythm.(Purpose) So this experiment is conducted to evaluate the effects of lighting regime and nutrient density on growth performance and welfare of broiler chickens.(Methods) A total of 1 080 day-old Beijing-You chickens were used with a 3 × 3factorial arrangement of treatments.All birds were given 23 hours day-length from 0 to 7 d of age to ensure adaptation to the research facility.At 8 d, the experimental treatments consisting of three lighting regimes will be randomly assigned to four rooms.The three lighting regimes are 23 L: 1 D (continuous), 16L: 8D (simulating natural lighting) and 16L: 8D (intermittent, 3L: 1D).The three treatments of nutrient density are high [starter diet: 12.33 MJ/kg apparent metabolisable energy (AME), 21.40% crude protein (CP) ; finisher diet: 13.17MJ AME/kg, 16.30% CP], middle [starter diet: 12.12 MJ/kg apparent metabolisable energy (AME),21.00% crude protein (CP); finisher diet: 12.96 MJ AME/kg, 16.00% CP] and low (L, starter diet:11.91 MJ AME/kg, 20.60% CP; finisher diet: 12.75 MJ AME/kg, 15.80%CP) energy and protein levels.All chickens were randomly allocated to 12 treatments with each treatment comprising 4 replicates of 30 chickens.(Results) Lighting schedules showed no difference in growth Performance at the end the experiment (P >0.05).Birds on low density diets had higher feed conversion ratio (FCR) (P < 0.05).In many cases comfort behaviors virtually disappeared in birds given 23 hours of light.This study aims to determine the reasonable light regime and nutrient density for the health and efficient production of broilers.