Abstract: Divergences were discovered in cell morphology, mode of cell division and passage of cell differentiation, when embryogenic calli induced from leaves of ‘Xushu 18’ sweet potato were suspension-cultured in modified MS medium with different concentrations of 2, 4-D. Cells grew quickly and divided equally in medium containing 1 mg/L 2,4-D. When 2,4-D was deleted, the cells divided unequally and developed into embryos. Extracellular pemxidase isozyme patterns changed greatly during suspension culture with different concentrations of 2,4-D and were closely related to cell development process.