By means of photography the author has investigated the mechanism of wave and current motion to measure simultaneously orbital path, velocity and acceleration of water particles.This new experimental system consists of a camera, a special light source, an intermittent exposure unit and a chemical liquid tracer. On the basis of theoretical analysis of combined effects of current and wave and the results of experiments, a model of total wave and current velocity is provided to calculate wave-current forces on a pile according to Morison's Formula.The calculated results from three different sets of wave and current data have been compared with experimental data and they are found in excellent agreement.