Abstract: With a large number of rural labors seeking employment opportunities in non-farm sectors, China has experienced significant decline, aging and feminization of its agricultural labor force. One solution to these problems is to develop agricultural mechanization. The paper studies the complement of machinery services for the demographic change of rural households and its constraints. Based on the survey data from Jiangsu and Anhui Province, and applying a Probit model, this paper estimates the effect of agricultural labor characteristics and land fragmentation on the adoption of agricultural machinery socialized service. Results show that for ploughing and harvest, 70.54% and 66.83% households fully rely on the purchased machinery service. Due to lack of physical strength and skills, elderly and women in rural area prefer to purchase agricultural machinery services. Meanwhile land fragmentation in rural area is a big hurdle to the adoption of agricultural machinery. Finally, this paper suggests that to promote the development of agricultural mechanization, the government should promote the development of agricultural machinery services market and encourage the consolidation of arable land.