A scale model of power tiller-trailer system with the same kinematic characteristics was constructed one eighth of the actual size to validate the effectiveness of mathematical model of motion. The parameters for the scale model of power tiller-trailer system were measured by a series of laboratory experiments. Validation tests for the: scale model was conducted under several ground and operating conditions. The tests were performed on artificial ground surfaces with several kind, of slope and obstacle. The travel path of the scale model was photographed successively in three directions. The travel paths obtained from both the film analysis and the simulation model appeared to be consistent with each other. It was concluded that the simulation model could be used to predict the motion of actual power tiller-trailer system if the parameters for actual power tiller and trailer are provided.