对早柳和小青杨的年轮宽度、年轮密度、木材纤维长度和干缩率及其径向变异进行了研究．结果表明，木材物理特性受年轮年龄的影响显著，而纤维长度不受年轮宽度影响．综合材质物理特性的径向变异规律，可将旱柳和小青杨整个生长期划分为４个时期：幼林期、速生期、成熟期和更新期，确定了各生长期的年龄值． The annual ring width, annual ring density, wood fiber length and dry shrinkage and their radial variations of early willow and young poplar were studied. The results show that the physical characteristics of wood are significantly affected by the annual growth age, while the fiber length is not influenced by the width of the annual rings. According to the radial variation of the physical properties of the material, the whole growth period of Salix psammophila and Populus simonii can be divided into four periods: young period, fast-growing period, mature period and renewal period, and the age value of each growth period was determined.