To explore the degeneration problem of cutting seedling caused by age effect in white poplar we chose hardwood cuttings of different ages of triploid hybrids white poplar ‘Beilinxiongzhu 2’ as experimental material and observed growth morphology of seedling, photosynthetic characteristics, root development characteristics, anatomatical structure of bark, total soluble sugar (TSS), total soluble protein (TSP), chlorophyll (Chl), proline (Pro), gibberellin (GA), auxin (IAA), abscisic acid (ABA) and IAA/ABA. The results showed as follows: (1) height growth, leaf area, petiole length, internode length, base diameter, main root number, main root length, rooting percentage, root effect index and net photosynthetic rate (P_n) decreased with the increasing of cuttings age. While lateral root number, lateral root length, intercellular CO₂ concentration (C_i), transpiration rate (T_r), stomatal conductance (G_s) were not affected by cuttings age. (2) Anatomical structure of stem bark showed that periderm and xylem thickened with the increasing of cuttings age. However, the thickness of phloem was basically similar among different ages of cuttings. (3) With the increasing of cuttings age, contents of soluble sugar, soluble protein, chlorophyll, gibberellin, auxin, IAA/ABA in seedling leaves gradually decreased, in opposition to the change in contents of proline and ABA. Comprehensive analysis showed that accumulated age effects led to the general senescent growing status in seedling of cuttings.