Abstract: In this study, we investigated the survival rate of Betula platyphylla Sak. calli treated with different concentrations of ethyl methane sulfonate (EMS) and treatment times. Half of the calli died under high-concentration EMS (for 1 or 2 h) or lowconcentration EMS (for 5 or 6 h). Mutation resulted in varied numbers of chromosomes in induced calli. The ratios of diploid, aneuploid and polyploid of induced calli were higher than those of controls. EMS exacerbated the extent of ploidy change in callus cells.