Abstract: Based on 441 micro survey samples of farmers, this study analysised the impact of aging rural labor force on chemical input from the aspects of various fertilizer use, pesticide use and purchase cost, and explored the impact mechanism of aging rural labor force from the aspects of physical condition, sense of control, skill demand, risk attitude and interpersonal relationship, so as to further investigate the individual characteristics of rural elderly labor force the heterogeneity effect on chemical input. The results showed that the aging of rural labor force would significantly reduce the application amount of compound fertilizer and the purchase cost of chemical fertilizer. The aging still had a significant negative impact on chemical input after controlling the variables such as physical strength and skill demand, which indicated that the physical strength and technology adoption speculated in previous studies were the ways for aging to affect farming, and the impact mechanism could not be fully revealed. Further research shows that aging of rural labor will affect the interpersonal relationship of farmers and the risk preference on farming input marginal effect. The conclusion shows that the policy of building ecological and livable beautiful countryside in China can promote the national food security strategy.

Key words: aging labor force, food security, chemical input, interpersonal relationship, risk preference, mechanism research