Abstract: In order to breed a fast-growing species with high tolerance to less favorable environment in northwest and northen regions of China In 1957, Populus simonii as female parent was crossed with mixed pollens (in 1:8) of P. pyramidalis and Salix matsudana used as male parents. Created by this combination were hybrid seedlings, from which 10 best young trees were selected to form a new cultivar named 'POPULARIS' which including 10 individual clones (CV. 35-CV. 44).The tests for identifying the characteristics of 'Popularis' shows that 'Popularis' possess the following advantages: fastgrowing, high efficiency of photosynthesis, tolerance to salinealkali soil, drought-resisting, resistance to Cytospora and Dothiorella diseases as well as fine timber quality.Its isoenzyme analysis and immunochemistry test also show that Salix plays a part in crossing produre.Regional tests have proved that 'Popularis' is suitable to grow in the Northwest, North and Northeast China.