The study was conducted to investigate the effects of different levels of cysteamine supplementation in basal diets on growth performance, meat quality and antioxidant ability of yellow broilers. Seven hundred and fifty yellow broilers at the age of 21 d were selected and allotted to 3 groups in a random design. Each group consisted of 5 replicates with 50 broilers in each replicate. After pre-feeding for 1 week, broilers were fed diets supplemented with 0, 60 and 120 mg/kg cysteamine, respectively, and the experiment was finished when the broilers grew to 63 d. The results showed that dietary supplemented with 120 mg of cysteamine per kg diets increased the average daily gain (ADG) and average daily feed intake (ADFI) of broilers at 22～42 d old (P<0.05)，but did not affect the feed to gain ratio (F/G) of broilers at 22～42 d old and the ADG, ADFI and F/G of broilers at 43～63 d old(P>0.05). Supplementation with 60 mg/kg cysteamine increased pH45 min, intramuscular fat content and tenderness of muscle in broilers about 63 d old, and also decreased lightness (L*45 min) of muscle (P<0.05). Supplementation with 60 and 120 mg/kg cysteamine increased water-holding capacity of muscle in broilers at 63 d old (P<0.05). Glutathione content in serum and muscle, glutathione peroxidase (GSH-Px) activity and total antioxidant ability in muscle of broilers at 63 d old were also increased by supplemented with 60 mg/kg cysteamine (P<0.05). Supplementation with 60 mg/kg cysteamine had a trend to increase the hydrosulphonyl content and tend to decrease the malondialdehyde content. Supplementation with 60 mg/kg cysteamine increased the superoxide dismutase, GSH-Px, adenosine monophosphate deaminase 1 and peroxisome proliferator-activated receptor-γ gene expression in muscle of broilers at 63 d old. In conclusion, supplementation with 120 mg/kg cysteamine in diets of broilers at 22～63 d old increased the growth performance of broilers at 22～42 d old; and supplementation with 60 mg/kg cysteamine in diets improved the water-holding capacity, intramuscular fat content, tenderness and pH of muscle and antioxidant ability of broilers at 63 d old.［Chinese Journal of Animal Nutrition, 2009，21(6):916-923］