With the restriction of the household land holding,the nonagricultural income has gradually become the main income of the rural household,which reduces the labor effort and its contribution to the agricultural highquality growth.Based on the agricultural production function with the labor effort,the contribution of the labor effort to the quality of agricultural growth is estimated after it being isolated from other factors.The results show the labor effort under the restriction of the land holding makes 72.5% of the contribution to the improvement of agricultural highquality growth from 1985 to 2016,which accounts for 41.8% of the agricultural quality growth in the same period and shows a gradual decline,but the decline rate tends to slow down.In general,this decline is more dramatic in developed regions,while in developing regions or large agricultural provinces it is just the opposite.Therefore,it is suggested to promote the transfer or exchange of land management rights,expand the land area of the household and improve their labor effort,so as to increase the market power of highquality agricultural development.