This experiment was carried out to develop the new synthetic breed (5/8 Charolais 3/8 Korean native cattle) with the importation of Charolais traits to Korean native cattle from 1979 to 1985. The phenotypic correlations between body weights and measurements of Korean native cattle (K), Charolais first crossbreed (F₁), Charolais back crossbreed (F₂) and Synthetic breed (S) at 3 and 12 months of age were estimated. The results obtained were summarized as follows 1. The phenotypic correlation coefficients of each breed between body weights and measurements were positive. 2. The chest girth was the most highly correlated with body weights in each breed. 3. The ranges of correlation coefficients between body weights and chest girth of K, F₁, B₁ and S at 3 and 12 months of age were 0.673-0.894, 0.72a-0.936, 0.472-0.897 and 0.601-0.921, respectively.