Abstract: In order to study the effect of high pressure processing on water bamboo (Zizania caduciflora L.) juice, this study compared the effects of high pressure processing (HPP, 400~500 MPa/5~10 min) and conventional heat treatment (TP, 80 ℃/10 min) on the physicochemical quality, nutritional components, antioxidant properties and volatile flavor components of non-concentrated reduced (NFC) water bamboo juice. The results showed that the sensory quality of heat-treated water bamboo juice was reduced and significant stratification occurred, while HPP treatment had no significant effect on pH, soluble solids and titratable acid content in water bamboo juice (P>0.05), and reduced stratification and improved the sensory quality of water bamboo juice. Meanwhile, compared with TP treatment, HPP treatment could better maintain the total phenols, flavonoids and DPPH free radical scavenging rate in water bamboo juice. In addition, gas chromatography-ion mobility chromatography (GC-IMS) flavor analysis showed that HPP increased the fruit and herbaceous aromas in water bamboo juice, which enhanced the flavor of water bamboo juice. In conclusion, compared with the traditional TP treatment, the HPP treatment had significant advantages in maintaining the quality characteristics, antioxidant and flavor of water bamboo juice.