Abstract: Duck breasts were used as raw material to simulate the process of Chinese traditional salted duck and explore the effect of repeated boiling of braised soup on the contents of heterocyclic amines as well as the precursors in duck breast and the corresponding soup. The results showed that with the increase of the using cycles of braised soup,the contents of creatine,free amino acids and glucose both in braised soup and in duck breast increased significantly(p<0.05)and the rate of the increase of precursors in braised soup was higher than that of duck meat. In addition,the total amount of heterocyclic amines in duck breast and the corresponding soup increased linearly with y=0.0224x+1.7209(R²=0.9871)and y=0.0157x+0.3821(R²=0.9442),respectively. After 40 times of boiling,the total amount of heterocyclic amines in soup and breast was 1.08 and 2.74 ng/g,respectively. The content of the creatine,free amino acids,glucose and heterocyclic amines both in duck breasts and the corresponding soup increased with the using cycles of the braised soup. Therefore,the repeated using of braised soup should be avoided.