The subsidy policy for the purchase of agricultural machinery and China's Agricultural Mechanization Promotion Law have been implemented since 1998 and 2004, respectively. The goal of the policy and the law is to improve the agricultural mechanization level (AML) in China. Policymakers expect that the AML could be increased by improving the agricultural equipment level (AEL). The AML in China is affected by many factors. However, only a few studies have investigated the effects of the AEL on the AML. To fill this gap, we built an integrative conceptual framework and estimated a corresponding structural equation model (SEM) using the relevant data collected from 30 provinces (cities and districts) in mainland China. The relevant data cover the years from 2001 to 2014. There are six factors in our framework, including AEL, level of economic development, land resource endowment, benefit factors, policy and environmental factors, and demographic factors. The results showed that the AEL had the greatest impact on the AML. The level of economic development, the demographic factors, and the benefit factors not only directly affected China's AML but also indirectly affected the AML through the AEL. Meanwhile, land resource endowment and policy and environmental factors had only an indirect effect on the AEL. This report can be used to inform the government that the improvement of the AEL is one of the important ways to achieve the comprehensive mechanization of China's agriculture, that the agricultural machinery purchase subsidies must still be enhanced and that the enforcement of China's Agricultural Mechanization Promotion Law must still be strengthened.Sustainability 2019, 11, 51 2 of 16 rural laborer, and low farmer income levels [3]. These conditions effectively prevent China from following the development path of using large-scale agricultural machinery, like that purchased by farmers in European and American countries. Correspondingly, China cannot follow the path of using small-scale agricultural machinery with higher value, like that purchased by Japanese and Korean farmers. With the development of agricultural mechanization, however, China has explored its own road to mechanization.China's agriculture has experienced a large expansion of machine investments by farmers and machine rental services provided by specialized agents, which has contributed to the mechanization of agricultural production [4][5][6]. Previous literature on the agricultural mechanization in China has concluded that the agricultural mechanization has increased the grain yield and ensured food security in China [7][8][9]. At present, the agricultural mechanization in China is in the transition period from whole process mechanization to comprehensive mechanization [10]. The development of agricultural mechanization was consistent with China's new-type urbanization [11]. Because of the continuous advancement of China's urbanization process and the massive transfer of rural labor, China's agriculture is developing toward a reliance on more mac...