Abstract: Soil infiltrability influences applied irrigating water transferred into soil water and the surface rainwater runoff responsible for soil erosion. Therefore it is very important to quantify the soil infiltrability. A method for measuring the soil infiltrability on hill-slope was advanced for the purposes. Algorithms were also formulated. From the principles of the method, an integrated experimental system was developed. Laboratory experiments were conducted. A digital camera was used to record the advance process of the area wetted by the run-on water flow at the soil surface. The mathematic models were derived to compute the soil infiltrability. Results show that the advances in wetted areas and the infiltrability as function of time are fitted with exponential functions. Compared the cumulative infiltrated water with the total supplied water, the relative estimation error is 6.1%, The accuracy of the method is higher. The dynamics of the infiltration curve conceptually present the infiltrability of a soil. The results validate the rationality of this measurement method, the computational models as well as the experimental procedures. This method can be used for faster field measurements for soil infiltrability with less water requirment. This will supply a foundation for the further study in this direction.