Abstract: This paper analysed the genetic variation of the stem form characters in 1-69 poplar × Simon poplar and 1-69 poplar × Nigra poplar F1 clones, which indicated that it is possible to select directly for stem form. In, order to tap adequately the potential of stem form improvement and to provide theoretical foundation for mult-generation breeding, the possibility of selecting indirectly for stem form from the tree crown structure was studied. The analysis of ge-notypic correlation provided the asseciations of different characters composing of tree crown to stem form and path-analysis analysed concretely their direct and indirect effects so as to determine the ideal crown form for stem form improvement of two different F1 clones. Based on the comparison among the results of selecting indexes of stem form of different characters combinations, the stem form estimates of different clones were taken by the most reasonable selection equations. By means of the comparison of the results of stem form selection to those of growth selection, the possibitity of improving simultaneously growth and stem form was concretely reviewed.