Abstract: Derivative tractor derived from walking tractor has excellent capacity of slope climbing, handling and braking, and the high transportation velocity, which has been used widely in China with the farm transportion demand increasing in recent years. At present,due to the influence factors such as the technology and the plant conditions, the all round properties of derivative tractor must be improved. Because of the transportation conditions in China countryside, especially in south part, there are more hills and worse road, it is very necessary to study the braking deceleration and the braking distance of derivative tractor on slope. This paper establishes the braking deceleration and the braking distance mathmatical model of derivative tractor on slope, then taking the Fuqiang 18Y derivative tractor as an example, the influence of the position of the centroid adhensive coefficient and the angle of grade on braking deceleration, braking distance, and the effect trend and degree were analyzed.It can provide theoretical foundation for designing derivative tractor.