The effects of constant high ambient temperature on growth performance and nutrient digestibility of growing pigs were investigated in this study. Nine healthy Landrace×Large white male pigs with average initial weight of (30±1.16) kg and the same genetic backgrounds were randomly divided into 3 groups with 3 replicates in each group and 1 pig in each replicate: constant high ambient temperature at 33 ℃ with ad libitum feeding (group Ⅰ), constant optimal ambient temperature at 23 ℃ with ad libitum feeding (group Ⅱ), and constant optimal ambient temperature at 23 ℃ but pair-fed to the amount consumed by the group Ⅰ (group Ⅲ). The feeding trial lasted for 21 d. The results showed that: 1) ADFI and ADG in group Ⅰ were lower than those in group Ⅱ (P<0.05); 2) the digestibilities of DM and gross energy (GE) in group Ⅰ were lower than those in group Ⅱ (P>0.05), while the digestibilities of CP and ether extract (EE) in group Ⅰ were a little higher than those in group Ⅱ (P>0.05). In conclusion, constant high ambient temperature resulted in a rise of digestibilities of CP and EE and a decrease of ADFI,ADG and digestibitities of DM and GE.［Chinese Journal of Animal Nutrition, 2009，21(6):982-986］