Based on the data set about crop production and irrigation of 31 provinces during 2003-2010 in China, this study applies the stochastic frontier equation (SFA) to measure crop technical efficiency and irrigation efficiency, and then builds a simultaneous equation model (SEM) to analysis their interaction mechanisms and their common factors. The result shows that crop technical efficiency and irrigation efficiency have a significant positive interaction~ Irrigation proportion, irrigation rate, reservoir capacity proportion and household oper...