This experiment was conducted to study the effects of ring die parameters on pellet quality and growth performance of broilers. By fixing the diameter of die hole (3.0 mm) and changing the length-radial ratio of die hole (6:1, 8:1 and 10:1), fixing length-radial ratio of die hole (10:1) and changing diameter of die hole (3.0, 3.5 and 4.0 mm) to produce 5 kinds of pellets feed with different diameter and hardness. A total of 864 broilers with similar body weight were randomly allocated into 6 groups with 8 replicates per group and 18 broilers per replicate. Broilers in the groups Ⅰ to Ⅴ were fed the pellet feed which the diameter and length-radial ratio of die hole were 3.0 mm and 6:1, 3.0 mm and 8:1, 3.0 mm and 10:1, 3.5 mm and 10:1, 4.0 mm and 10:1, respectively; broilers in the group Ⅵ were fed the pellet feed which the diameter and length-radial ratio of die hole were 3.0 mm and 10:1 at 22 to 35 days of age, and 4.0 mm and 10:1 at 36 to 42 days of age. The experiment lasted for 21 days. The results showed as follows:1) in the same diameter of die hole, the pellet hardness was significantly increased with the length-radial ratio of die hole increased (P<0.01). In the same length-diameter ratio of die hole, the pellet hardness was significantly increased with the diameter of die hole increased (P<0.01). There was no significant difference on pellet durability index (PDI) among all groups (P>0.05), and all PDI was higher than 95%. 2) In the same diameter of die hole, with the pellet hardness increased, the final body weight and average daily gain were decreased, while the ratio of feed to gain were increased. The final body weight and average daily gain of group Ⅰ were significantly higher than those of group Ⅲ (P<0.05 or P<0.01), the ratio of feed to gain of group Ⅰ was significantly lower than that of groups Ⅱ and Ⅲ (P<0.05). 3) In the same length-diameter ratio of die hole, there were no significant differences on the final body weight, average daily gain and average daily feed intake among all groups (P>0.05). The ratio of feed to gain was decreased with the diameter of die hole increased, and the ratio of feed to gain of group Ⅲ was significantly higher than that of group Ⅴ (P<0.05). In conclusion, the length-radial ratio and diameter of die hole can significantly increase the pellet hardness. In a certain scope, increasing pellet hardness can reduce the final body weight and average daily gain, raise the ratio of feed to gain, while increasing the pellet diameter can decrease the ratio of feed to gain.