This research was aimed to study the effects of different conditioning temperatures and particle sizes on growth performance and nutrient apparent utilization of broilers. This test was designed by corn-miscellaneous meals poultry complete compound feed for the test material. Four different sieve pore sizes (1.5, 2.0, 2.5, 3.0 mm) and 2 different conditioning temperatures (75, 85 ℃) were selected. A total of 864 one-day-old Arbor Acres (AA) broilers were randomly divided to 8 groups with 6 replicates per group and 18 broilers per replicate. The experiment lasted for 6 weeks. The results show as follow: early period (1 to 3 weeks), apparent utilizations of dry matter and crude protein were not significantly different among all groups (P>0.05). Later period (1 to 3 weeks), apparent utilizations of dry matter and crude protein were significantly affected by conditioning temperature, particle size and interaction of them (P<0.05). Final body weight, average daily gain and average daily feed intake of early period were significantly affected by condition temperature (P<0.05). Final body weight, average daily gain and average daily feed intake of early period, final body weight and average daily gain of later period, and average daily gain of whole period were significantly affected by particle size (P<0.05). The average daily feed intake and feed to gain ratio of later period were not significantly different among all groups (P>0.05). In conclusion, the growth performance and nutrient apparent utilization of broilers are significant impacted by particle size. In order to reduce energy consumption of processing, poultry feed appropriate condition temperature should be 85 ℃, particle size should be 911 μm (sieve pore size of grinder is 3.0 mm) of early period; and appropriate condition temperature should be 75 ℃, particle size should be 901 μm (sieve pore size of grinder is 3.0 mm) of later period.