The relationship between farmers and land has always been the main concept behind rural reforms in China, and continues to be so even at present. Land fragmentation management as one of the basic characteristics of agricultural production in our country, not only related to agricultural production, but also related to the use of labor. Using household survey data collected from the Jiangsu province in China, this study analyzes the theoretical mechanism, and empirically tests the direction and degree of the impact of land fragmentation on non-agricultural labor supply. The results reveal that land fragmentation decreases the marginal productivity of agricultural labor and increases the non-agricultural labor supply. This effect is especially more obvious for young workers. The government should provide timely policy support to spontaneously transfer adjacent land or the whole village among farmers, promote land consolidation, optimize the agricultural management system, complement agricultural modernization with new urbanization, and propel the integration of the agriculture, manufacturing, and service industries in rural areas Acknowledgement : This study was supported by the National Natural Science Foundation of China (No. 41561040); the Key Projects of the National Social Science Fund of China (No. 15AZD075); the Sixty-second Batch of China Postdoctoral Science Foundation Funding (No. 2017M622097); the Technology Foundation of Jiangxi Education Department of China (No. KJLD14033 & No. GJJ160431), and the Fok Ying-Tung Fund (No. 141084).