Abstract: In order to assess the improving effect of dietary supplementation of glutamine on growth performance and meat quality in broilers exposed to circular high temperature, a total of 300 22-day-old AA broilers were chosen and randomly divided into five groups, including one control group （fed basil diet） and four circular heat stress treatment groups （supplementing 0, 0.5%, 1.0% and 1.5% of glutamine in basil diet）; at the end of the experiment, the indexes associated with growth performance and meat quality of the broilers were determined and statistically analyzed. The results showed that the circular heat stress significantly decreased the average weight gain （P〈0.05）, average feed consumption （P〈0.05）, a＊ and b＊ value and pH45min and pH24h value of thigh （P〈0.05）, and pH45min and pH24h value of breast （P〈0.05）, and significantly increased the L＊ value and water loss of thigh and breast （P〈0.05）; supplementation of 1.5% of glutamine in basil diet significantly increased the average weight gain （P〈 0.05）, average feed consumption （P〈0.05）, a＊ and b＊ value of thigh （P〈0.05）, and pH45min value of breast （P〈0.05）, and significantly decreased the L＊ value of breast （P〈0.05）. These results indicate that dietary supplementation of glutamine improves growth performance and meat quality in broilers （22- to 28-day-old） under circular heat stress.