Applying the transcendental logarithmic Stochastic Frontier Analysis (SFA) model to estimates the cost efficiency of wheat production in 15 wheat producing provinces from 1994 to 2016,this paper then employs Spatial Durbin Model (SDM) to calculate the direct influence and spatial spillover effect of agricultural mechanization on the cost efficiency.The main findings include that the cost inefficiency is 17.3%,and the direct influence and spatial spillover effect on grain cost efficiency are noticeable,which means that interregional-service of agricultural mechanization has a positive effect on the grain cost efficiency of local region and the regions surrounding it.This testifies the reality that agricultural mechanization service is achieved among localities with different longitudes in China in terms of spatial distribution.From the perspective of time,the year 2004 is a divide,after which the spatial spillover was evidently manifested.As suggestion,it is proposed to give priority to agricultural machinery service organizations in allowance distribution,to construct and advocate the agricultural machinery information platform,and to distribute grain production along longitude.