Abstract: Alnus nepalesis intercropping with crops can improve the growth of crops． Traditionally，farmers are used to applying 6000～7500kg fresh leaf of Alnus sp．per hectare as the substitute of livestock fertilizer within the rice plantation because the fertility of 1000kg dry leaves of Alnus sp．equal to 14．3kg nitrogenous fertilizer，2．4kg phosphorus and 2．2kg kalium respectively．This article has described and analyzed the Alnus nepalesis-based mountainous intercropping and fallow system in Himalayan region from the cases of Northeast Indian and Yunnan Province of China．