The highest cutting ratio and the best growth performance of the P. albs, P. albs × P. glanduloscr and P. glandulosa were at -0.05 bars of soil water potential (Ψ_s). Their growth and rooting ability of cuttings were better in suitable soil moisture contents, 19.650, but were worse in low soil moisture contents, 11.41% and 16.66%, respectively. Specially, P. alba × P. glandulosa appeared hybrid vigor in high soil water potential (Ψ_s= - 0.05 bars) but not appeared it below Ψ_s = -0.5 bars. It is believed that P. glandulosa is a natural hybrid between P. davidiana and P. alba in view of morphological characteristics. Aspen, normally, does not have the rooting ability of cuttings, however, P. glandulosa showed the rooting ability, though the ratio was low, 23%. It is estimated that this rooting ability was originated from P. alba. In addition, its growth rate was between P. alba and P. davidiana, and the sensitivity of water requirement for the growth was also really equal to P. alba. This facts prove P. glandulosa to be natural hybrid between P. alba and P. davidiana.