This study was carried out to compare the characteristics of relative conductivity(RC) in the twenty -one deciduous broad-leaved species. The results obtained were summarized as follows 1. The RC ranged from 3.18 × 10^(-15) to 1.23 × 10^(-10) ㎡ in deciduous broad-leaved species, and appeared different values in various portions of a tree and species. 2. In eight diffuse-porous species, the ranges of average RC were 3.49 × 10^(-13) to 6.35 × 10^(-11) ㎡ in stems. 4.89 × 10^(-13) to 2.99 × 10^(-11) ㎡ in branches, and 1.33 × 10^(-13) to 9.42 × 10^(-12) ㎡ in junction part between stem and branch. In thirteen ring-porous species, the RCs were 7.14 × 10^(-13) to 4.76 × 10^(-11) ㎡ in stems, 2.93 × 10^(-13) to 3.91 × 10^(-11) ㎡ in branches, and 1.41 × 10^(-13) to 9.20 × 10^(-12) ㎡ in junction part. 3. The RC and diameter of stem have no interrelation in eight diffuse-porous species. The RC of stem increased with decreasing diameter of stem in eleven ring-porous species except Fraxinus mandshurica and Maackia amurensis. 4. In five deciduous broad-leaved species, the RC of 1-year-old shoots(the leader and adjacent laterals ) ranged from 4.87 × 10^(-13) to 8.41 × 10^(-11) ㎡ in the leaders, and 7.93 × 10^(-14) to 2.01 × 10^(-11) ㎡ in the adjacent laterals. The RCs were much greater in the leaders than in the adjacent laterals because of the hydraulic dominance of the leader shoot.