The Mechanization of Agriculture and the Transformation of Agricultural System in the Post-Bellum American South Meng Haiquan(106) Based on historical data, the author argues that between the 1920s and the 1960s the small-scale tenant farm system in the American South, based on the labor mode of individual family, was gradually transformed into a largescale modern capitalist farm system based on the labor mode of employment. The author stresses that the basic force of the transformation is the mechanization of agriculture.