Abstract: With temperature decreasing, waxy crude oil is gelled. For the formation of wax crystal structure in this process, the entire crude oil system appears the thixotropy, which plays a decisive role in the shutdown and restart pressure calculation of oil pipeline. The hysteresis curve method is used to study the thixotropic process of Daqing and Mahui Crude oil. Results show that the hysteresis curve area characterizes the thixotropy of relative strength of waxy crude. And its logarithm displays a linear decrease with the increase of temperature. And the deviation values are within 1%. At the temperature range near the set point of waxy crude, the deviation of yield value measured by the hysteresis curve method and SY/T 7547-1996 recommended is within 10%. Specially, when the temperature is near the set point, the deviation value is minimum.