The relation between the survivors of micro-organisms and the processing pressure and the pulse pressure processing was investigated in UHP treatment to watermelon juice.And species of baroduric bacteria were discriminated.Processing pressure is between the atmosphire pressure and 500 MPa,and the pressurized duration 10 min in this experiment.Results show that under the ambient temperature (30 ℃) and pressure equal to or above 400 MPa the number of natural microflora,yeast,mold and coliform bacteria meets t...