Abstract: The disc tension infiltrometer was limited to measure soil hydraulic conductivity because it is difficult to calculate the results from the three-dimensional infiltration process. In this paper, the three-dimensional infiltration was changed to one-dimensional infiltration of disc tension infiltrometers to measure soil hydraulic conductivity in situ, which simplified the calculating processes. The results show that a significant correlation between steady infiltration rate and hydraulic conductivity in the limited one-dimensional infiltration, and the same results are gained from double-disc tension infiltrometer. However, the results from three-dimensional infiltration are bigger than that from one-dimensional infiltration. Distinct differences among one-dimensional infiltration, steady and transient calculating methods are observed. The double-disc tension infiltrometer is a good equipment for determining soil hydraulic conductivity.