Abstract: The test material used in the study was the poplars planted in Baoding, Heibei Province, whose wood basic density, fiber length and width were analysed. The result reveals that: (1) there are obvious differences between the wood basic density and fiber length of different hybrid combinations and individuals. The differences between wood basic density and growth property is not significant; (2) the two properties can be selected separately, therefore the new poplar hybrids which has high wood basic density, long fiber length and fast-growth can be selected. (3) the relationship of wood basic density between juvenile and adult wood is significant, so the early selection can be adopted in poplar breeding. The crossing, which P. deltoides cv. ‘Lux' was used as mother plant and P. mgra the father plant and inter species hybrids, was the best combination for selecting fast-growing and good quality poplar in the North China area.