In order to investigate biomass yield of one-year-old hyblrid poplars, Pripulusalba x P. glandulosa $F_1$ and Populus nigra var. italica x P. maximowiczii $F_1$clones, as energy and fiber resources, dry matter yield, leaf area, leaf area index, dry matter production ability, specific gravity and fiber length and width were measured. Dry matter yield was 1.89 ton/ha for Poplus alba x P. glandulosa $F_1$ and 3.63 ton/ha for Populus nigra via.italica x P. merximowiczii $F_1$ clones in the planting density of 20,000 trees/ha and in the planting density of 40,000 trees/ha was 3.87 ton/ha for Populus alba x P. glandulosa $F_1$and 5.64 ton/ha for Populus nigra var. italica x P. maximowiczii $F_1$ clones. Leaf area index was 1.24mtim2 in the planting density of 20,000 trees/ha and 2.45 m31m3 in the density of 40,000 trees/ha for Populus alba x P. glandulosa $F_1$ clones and it was 1.96 m21m2 in the planting density of 20,000 trees/ha and 3.36 m21m2 in the density of 40,000 trees/ha for the hybrid $F_1$ Populus nigra var. italica x P. maximowiczii clones. The average specific gravity of the hybrid poplars was 0..36 when bark and pith were included and 0.31 when bark and pith were removed in the plot of 20,000 trees/ha and in the 40,000 trees/ha plot showed 0.35 and 0.31 respectively, for Populus alba x P. glandulosa $F_1$clones. It was 0.36 when bark and pith were included and 0.32 when bark and pith were removed in the 20,000 trees/ha plot and in the 40,000 trees/ha plot was 0.34 and 0.31 respectively for Populus nigra var. italica x P. maximowiczii $F_1$clones. The average fiber length was 0.57 mm in the 20,000 trees/ha plot and 0.58 mm in the 40,000 trees/ha plot for Poplus alba x P. glandulosa $F_1$clones and was 0.60 in both plots of 20,000 trees/ha and 40,000 trees/ha for Populus nigra var. italica x P. maximowiczii $F_1$ clones. There is a big clonal variation among those clones studied, showing high selection potential in both species.