The experimental studies were intended to clarify the effects of leaf yield calculations, and also aimed at estimating the correlations between some characters for the selection of desirable stocks of mulberry trees. The analysis of covariances was the variance components procedures in a replicated trial for the varieties, and also it was used to obtain the genotypic, phenotypic and environmental correlations between the eight characters-branch length, node number, branch diameter, branch number per stock, total branch weight, old branch weight, new shoot and leaf weight, and leaf weight, etc. The results obtained are summarized as follows: Phenotypic, genotypic and environmental covariances are shown in Table 1 and phenotypic correlations, genotypic correlations and environmental correlations are shown in Table 2. Genotypic correlations were slightly higher than the corresponding phenotypic correlations between the characters in the varieties, but the variation in values due to the change of environment appeared between the characters. Genotypic correlations between the leaf yield of mulberry trees and other characters indicated that high leaf yield was genetically correlated with six characters namely branch length, node number, branch number per stock, total branch weight, old branch weight and new shoot weight, etc. It was also observed that lower correlations were appeared between the leaf yield and branch diameter, and branch diameter and other all characters studied in both genotypic and phenotypic correlation coefficients.