随着我国山丘区农业机械化水平的逐步提高，如何合理配置坡地田间道成为山丘区农业机械化发展的瓶颈之一。针对目前路网密度设计大多针对高等级公路进行，而很少涉及田间道等等外级道路的现状，通过数学模型手段，建立了合理确定小流域坡耕地田间道路网密度的理论方法，并根据微分方程稳定性理论给出了模型的解，最后以重庆忠县虾子岭小流域为例，给出了使劳动生产率最大和道路修建成本最小的田间道路网密度值，为三峡库区小流域田间道路网的设计提供了一定的理论依据。

With the development of agricultural mechanization in China hilly region, how to allocate the field road network in sloping land reasonably has been one of the bottlenecks which restricted the development. The object of the previous road network density design was mostly aiming at the highway, whereas seldom involves the status of the off-rade road such as field road. A theoretical method with mathematic model has been established to determine the field road network density of sloping farmland in small watershed, and the solution of the model has been obtained according to the stability theory of differential equations. Using the Xiaziling small watershed in Zhong County as an example, the field road network density with the highest labor productivity and lowest construction cost has been given. The results can be helpful for the design of the field road networks in the small watershed of Three Gorges Reservoir regeon