Abstract: By regulating NH+4 and 2, 4-D content in medium, Populus simoom callus lines were established from its stems. Those callus produced a large number of friable sub-callus on its surface on the callus maintenance medium, which contains 4mg/L 2,4-D. So far, the callus lines could be subcultured. Five suspension cell lines were established from 3-month-old embrycgenic friable callus in liquid medium. The medium, which contains mineral salts, vitamius and inositol of MS medium and 2mg/L 2,4-D, 500mg/L casein hydrolysat, 1. Og/L 2-(N-morpholino) ethanesulfonic acid, 3% coconut milk, and 3 % sucrose, was optimal for growth of the suspension cells. Addition of CM, CH and MES into the liquid medium was benifical for the cells growth. There was a direct relationship between the growth rate of suspension cells and medium pH changes. The growth rate was slow when culture medium pH decreased within initial 3 days. Then it was fast when medium pH rose. The medium, which contained 2. 0mg/L BA and 0. 01 -0. 1mg/L NAA, could produce a large number of somatic embryogenesis from embryogenetic cell complex. The difference of ability is somatic embryogenesis among different cells lines was very remarkable. And different osmotic pressures could affected the produce of somatic embryogenesis. Plant regeneration on 1/2MS medium.