The swelling of clay results in the non-linearity at the lower pressure range of the relationship between water flow velocity and the pressure gradient. A threshold gradient exists for triggering the flow in the low-permeability porous media which is of vital importance in unconventional hydrocarbon recovery and radioactive waste disposal. In this study, experiments of 0.1M ionic strength NaCl solution flowing through mixtures of 10% clay and 90% sand columns are performed to measure the permeability and threshold gradients at temperatures ranging from 20℃ to 90℃. The non-linear parts of the flow velocity and hydraulic gradient curves are also measured and plotted to exhibit the process. The experiments are based on a customized core flooding system designed for high-precision measurement of hydraulic gradient and permeability of swelling bentonite. The liquid permeability and the threshold gradient are measured in a steady-state flowing condition by a high-precision differential pressure transducer connected to the ends of the column, as well as a high-precision flow meter. Experimental results show that the relationship between permeability and threshold gradient is a power-law correlation, as proposed by Birkholzer and Liu [1]. The results also indicate that higher temperatures lead to lower threshold gradients, as predicted by the continuum-scale two-parameter model for non-Darcian flow in low permeability porous media proposed by Chen [2]. The power-law relationship of permeability and threshold gradient at higher temperatures have smaller constants which reveal a left lower movement of the curves with higher temperatures, as indicated by the Chen model. This study takes advantage of a customized core flooding experimental system to investigate the role of temperature on the threshold gradient of non-Darcian flow in low permeability porous media