A new and efficient method for detection of the viable and dead cell of pure cultured of Vibrio parahaemolyticus was developed by using a DNA dye of ethidium bromide monoazide(EMA) in combination with the traditional polymerase chain reaction(EMA-PCR).The results showed that,under the light exposure for 20 minutes to photolyse the EMA in cell suspension of 108 CFU/mL Vibrio parahaemolyticus treated with EMA at the concentration of 1.4μg/mL,the PCR results were negative,but the control without treatment by using EMA,the PCR results were positive.The PCR for viable cell of Vibrio parahaemolyticus was not inhibited with the maximum concentration of EMA at 6μg/mL.After EMA treatment,the number of viable Vibrio parahaemolyticus cells in varying ratios of viable to dead cells could be selectively quantified by PCR.The minimum level of detection was 10 CFU/PCR reaction.A linear relationship was found between the relative fluorescent intensity of the DNA bands and the log of genomic targets derived from the viable cells in mixtures of viable and dead cells in the range of 10 to 2 × 105 CFU/PCR.