Abstract: To evaluate the effect of dietary supplementation vitamin D3 on growth performance， slaughter performance， immune function and meat quality of broilers， 200 one\|day\|old Avian broiler chicks were randomly divided into two treatments with five replicates of 20 chicks. The chicks in the control group were fed with a corn\|soybean basal diet and the chicks in the experimental group were fed with a corn\|soybean basal diet supplemented with vitamin D3（2 000 IU·kg-1）. The trial period was 42 days， including 2 weeks of preliminary feeding period and 4 weeks of trial period. The results showed that there was no significant difference in broiler production performance between the control chicks and experimental chicks（P>005）. In comparison with the control group， dietary vitamin D3 supplementation had no effect on slaughter weight， semi\|eviscerated weight， and eviscerated weight; the ratio of feed to weight increased by 3080% in the fourth week （P>005） ; the abdominal fat percentage was decreased by 2383%（P<005）. Moreover， the heart weight， liver weight， spleen index and bursa fabricius index in the experimental group were increased by 1093%， 2109%， 2705% and 4615%， respectively， compared with the control one， but there was no significant difference between two treatments（P>005）. Dietary vitamin D3 supplementation had no effect on meat quality of broilers.

Key words: Vitamin D3, broiler, production performance, slaughter performance, immune function, meat quality