Fresh-cut lotus roots were used to study the effects of ultra high hydrostatic treatments on the quality of lotus roots during storage.With the increase of pressure and holding time of extending,soluble solid and total phenol had little changes.The content of ascorbic acid,the activity of PPO and the frangibility of lotus roots decreased significantly (P<0.05).The high hydrostatic pressure treatment significantly inhibited the microbial growth (P<0.05).The sterilization effect was not increased with the prolonging of holding time,indicating that the instant pressurization and instantaneous unloading process played an important role in ultra high pressure sterilization.Further studies of ultra high pressure treatment on fresh-cut lotus root showed that the loss of Vc under UHP treatment was lower than that of the control but the soluble solids loss increased gradually during storage.The color of lotus root changed little.The high hydrostatic pressure treatment inhibited the PPO activity and the microbial growth.It was clearly demonstrated under the microscope that the high pressure damaged the cell structure of lotus root.