The experiment was conducted to evaluate the effects of interaction between vitamin A and vitamin D on calcium-binding-protein (CaBP) concentration in serum, CaBP mRNA expression in tibia and duodenum of broilers. Three hundred and eighty four 8-day-old Arbor Acre male broilers with similar body weight were randomly allotted into 16 treatments with 3 replicates each and 8 chickens in each replicate. The trial lasted for five weeks. The 16 treatments were formulated by the addition of 1 500, 3 000, 15 000 and 45 000 IU/kg of vitamin A and the addition of 500, 1 250, 2 500 and 5 000 IU/kg of vitamin D to the basal diet in a 4×4 factorial arrangement. The results showed as follows: 1) the CaBP concentration in serum, CaBP mRNA expression in duodenum and tibia of broilers showed a downward tend of linear (P=0.091, P=0.012, P=0.110) with the added levels of dietary vitamin A, and the addition of 45 000 IU/kg vitamin A group showed the lowest results; 2) the CaBP concentration in serum and CaBP mRNA expression in duodenum showed a upward tend of linear (P=0.31, P=0.14) with the added levels of dietary vitamin D, and the addition of 5 000 IU/kg vitamin D group showed the highest results; 3) there is no significant interaction between vitamin A and vitamin D in CaBP content in serum and CaBP mRNA expression in tibia and duodenum of broilers (P>0.05). The results showed that the possible mechanism by which excess vitamin A caused abnormal skeleton metabolism was that large amount of vitamin A in diet inhibited the expression of CaBP mRNA, especially, the expression of CaBP mRNA in duodenum, and then induced a reduction of serum CaBP content, and resulted in abnormal metabolism of calcium and phosphorus. It was probably related to antagonistic action of high levels of vitamin A on vitamin D that excessive vitamin A may decrease CaBP mRNA expression of broilers. ［Chinese Journal of Animal Nutrition, 2010，22（3）:571-578］