Abstract: The experimental apparatus was designed and made up of isotropous particles（pebble） in porous media. All the pebbles were unordered accumulation. The experimental research on the flow characteristics of nitrogen-water two-phase flow in channel was conducted. The porous media channels were consisted of the polymethyl methacrylate（PMMA） circular pipe which diameters are 60, 70 mm and stainless steel ball which diameters are 2, 4, 6, and 8 mm. The experimental results show that when the liquid flow is constant, the pressure drop between the inlet and outlet of the test section will lower with the increasing of the inner diameter of the test pipe, but higher by decreasing the diameter of ball or accelerating the nitrogen flow.When the inner diameter of the test pipe is invariable, increasing the diameter of ball can decrease the pressure drop between inlet and outlet of the test section. The expressions of pressure drop were obtained under this experimental condition by fitting.