Abstract: This article is aimed at studying height & DBH conditions of Populus×Xiaohei which was afforested by different ways of clonal reproduction in Bashang area of Zhangjiakou City,and takes Populus×Xiaohei which was afforested by clonal reproduction of Zhangbei County and Guyuan County as study object. Measured data were used of height & DBH(by ways of stem analysis)of Populus×Xiaohei which was afforested by cottage,mark-and-sweep and pile anchoring,and fitting was done for height & DBH models of Populus×Xiaohei afforested in three ways.The Logistic equation model for Populus×Xiaohei afforested by cottage,H=1/(0.1+0.559×0.724^D),(R²=0.992),logistic equation model for Populus×Xiaohei afforested by mark-and-sweep,H=1/(0.1+0.617×0.766^D),(R²=0.988) and power function model for Populus×Xiaohei afforested by pile anchoring have been built,H=2.458×D^0.524,(R²=0.964). The result indicates that the coefficient of determination(R²)of nonlinear regression models of three kinds are all greater than 0.96,D_1.3 can commendably account for height of each organ.

Key words: Bashang Area of Zhangjiakou City, clonal reproduction, Populus×Xiaohei, height-DBH model