Based on perspective of neoclassical economics,this paper explores the internal mechanism and constraints of agricultural intensification development.The result shows that agricultural intensification development is based on intensive management activities adopting modern agricultural technology，and it is the agricultural development process with the main feature of improving agricultural productivity or the level of intensification.However, agricultural intensification development of China is mainly constrained by the factors including agricultural products market demand and its price signals,the behavior of agricultural scientific research departments and agricultural materials firms,agricultural cluster degrees and the functions of the cooperation organization,agricultural infrastructure and agricultural human capital levels.Therefore,this paper proposes several policy suggestions on how to push forward China's agricultural intensification development:earnestly protecting the interests of migrant workers to promote the effective transfer of agricultural labor forces; improving public agricultural research sector incentives,optimizing the agricultural cultivation layout within provincial regions and optimizing the public investment structure of agricultural infrastructure and so on.