Abstract: At the beginning of the fourth industrial revolution, the first demographic dividend characterized by the labor number has gradually disappeared, and the second demographic dividend characterized by the high-quality human capital will become the important factor of the trade growth. Based on the binary of towns and cities, combining with causality test and impulse response analysis, this text discusses how quantity of labor force, quality of human capital and savings rate influence the foreign trade, finding labor force has a significant impact on China′s export trade, but the effect is decreasing; because of the time lag effect of education, labor quality has no significant influence on export trade, but it is becoming more important; high-savings is the characteristics of demographic dividend, and it has indirect effects on demographic dividend by converting into the capital.

Key words: binary of towns and cities, demographic dividend, export trade, Granger causality, impulse response analysis