Abstract: By innovated sweet potato of suiting industrialization development in china .we innovated using improved crossbreeding. and improve or utilize directly the cross offspring .the result show that the average seed rate of improved crossbreeding increased 20.8-32.3% and 14.6%~28.9% than directional pollination of manual and assistant pollination. The bred rate of the purple lines increased 7%~14% and 30.4%~62.2%.The good materials were bred which were parents of sweet potato such as Yan 164、80、194, lines as Yanzishu 653、176、323and posterities as Yanzishu 18、20.The good new variety of Yanzishu 337 was bred by this way too. The examination proved that the yield descendiblity of purple sweet potato progeny was controled by the additive gene and the descendiblity in the purple line bred rate was cortroled in part by the additive gene.