Abstract: Abstract：Some researches have already been carried out to discuss about the effect of rural ageing labor force on land transfer. Two main reasons for this effect are believed to be land complex and labor capacity restriction, which are both caused by aging. It is significant to clarify the relationship between the two factors in order to deepen the understanding of the effect of rural ageing labor force on land transfer. Using the national baseline survey data of CLDS (2016) and the intermediary effect model, this paper empirically tests the intermediary effect of land complex and labor capacity restriction on the influence of rural ageing labor force on land transfer, and make comparison between them . The results show that land complex and labor capacity restriction both show strong mediating effect. On average, the land complex of the elderly population can explain 16.37% of the probability of land supply, 12.34% of the supply area, 6.72% of the probability of land demand and 6.43% of the demand area. The labor capacity constraints of the elderly population can explain 40.10% of the probability of farmer land supply, 36.50% of the supply area, 12.34% of the probability of farmer land demand and 14.49% of the demand area. Compared with the land complex, the mediating effect of labor capacity restriction is stronger. Its comprehensive effect is that the aging of labor force significantly increases the land supply of farmers, and also significantly inhibits the land inflow demand of farmers. Therefore, with the aggravation of aging, the problem of rural land transfer market is not insufficient supply, but insufficient demand. In order to activate the effective demand of land circulation market, it is necessary to strengthen the cultivation of new agricultural management subjects, improve the level of agricultural automation and improve the compensation mechanism of agricultural land management.