The rheological properties and thixotropy properties of the pitaya juice treated at different heating temprature and different ultra-high pressure were investigated.The result showed that all the processed pitaya juice behaved as pseudoplastic fluid.At the low shear stress of 1~30 s-1,colloidal viscosity was decreased with the increase of treatment temperature.When the shear stress was more than 30 s-1,the sample viscosity were essentially the same with the control one.At the different high pressure,the highest colloidal viscosity was found at 400MPa;the colloidal viscosity at 300 MPa and 450 MPa were slightly higher than the blank sample.The colloidal viscosity was almost the same with blank samples at 350 MPa.For the thixotropy properties,the blank sample and high pressure treated samples all showed no thixotropy properties.But the samples of heat treatment behaved the thixotropy properties and the thixotropic loop area was decreased with the increase of treatment temperature.