Abstract: In order to investigate the effect of high hydrostatic pressure (HHP) on microorganism and flavor of fresh watermelon juice, HHP was applied to produce watermelon juice. Total bacteria, mold and yeast, typical flavor compounds of watermelon juice after HHP treatment of 600 MPa and 60 min were studied with thermal treatment of 95℃ and 1 min as control. The variations of microorganisms count and content of typical flavor compounds during 30 d storage at 4℃ were investigated. The count of total bacteria, mold and yeast of thermal and HHP treatments conformed to hygienic standards and shelf life could meet consumption demand. The treatment of 600 MPa and 60 min HHP induced little on typical flavor compounds. The content of typical flavor compounds did not change after 30 d storage at 4 ℃. In general, HHP treatment is suitable for fresh watermelon juice production.