The initial soil infiltration rate affects and determines rainfall runoff, hydrological processes and soil erosion process. A new experimental method and device were suggested to test the initial infiltrability of soil under ring infiltrometer. The water distribution in the soil profile as made by the initial infiltrated water was visually observed and the initial process of soil infiltration was estimated. The specially constructed ring could be disassembled into two halves so as to conveniently observe the distribution of the infiltrated water. The detailed structure of the special designed ring and its application methodologies were detailed. An infiltration ring made of plexiglass was used to comparatively observe the 1-D infiltration process with refilled soil of the same density. The diameter of the disassemble ring was 35 cm, as the standard. A series of infiltration experiments were conducted with silt loam taken from Beijing. The experiment involved three soil bulk densities, 1.2 g/cm3, 1.3 g/cm3, and 1.4 g/cm3 and three hammering energy levels, determined by the weights of hammers of 1 kg, 2 kg, 4 kg, freely falling down from 1 m height. Two liters of water were used for the observations in every experiment, with two replicates. The wetted soil volume in the ring showed that the actually wetted soil column by the infiltrated water consisted of the radial/horizontal infiltration caused by the gaps between the ring wall and soil and the vertical infiltration from the ground surface. The preferential flow between the ring wall and the soil significantly influenced the accuracy of the measured infiltration rate. The errors increased with the increase of soil bulk density. The observed initial infiltration, in terms of the radial infiltration width and the vertical infiltration depth was approximately equal. The depth of vertical infiltration was 1.001 times of radial infiltration width. The initial infiltration rate measured was 3.3 times of the simulated 1-D initial infiltration rate. This study will supply a method for assessing soil infiltration rate measured by ring infiltrometer.