The poplar bacterial canker caused byErwinia sp. is a serious disease spreading in most parts of Northeast China, where poplars are cultivated. The disease seriously infects those poplars belonging to sectionAigeiros or the intersection hybrids of sectionTacamahaca and sectionAigeiros and their clones. Five fine poplar cultivars resistant to the bacterial canker have been obtained by screening tests. They areLz 2 (Populus simonii ×nigra var.italica), A15(P. ×sp.), 613(P. xsp.), A102 and A98(P. ×simonii ×sp.). The following chemicals are obviously effective, such as: 50% DT germicide, 40% XF-136 and 10% C.C.M.A. or 12.5% ramphencol and 50,000 ppm/ml validamycin, with which the stems or the roots can be watered.