Based on the prediction of population from the United Nations and data dating from the reform and opening up,this paper analyzes the variation of relationship between our national labor force demand and supply under the assumption of variation of labor participation rate, growth rate of three tertiary industry production value and employment structure adjustment before 2030. The results show that the turning point of the labor force is approaching and the limitless for labor force supply has come to the end as the negative effect of the population structure on labor force participation rate is increasing and the labor participate rate of the youth is decreasing.In the long term, the secondary and the tertiary industry will absorb labor force efficiently with the adjustment of the industry structure,while the primary industry will crowd out the labor force;the prediction results show that the relationship between labor force demand and supply will be inversed at the end of 13th five-year-plan, and the relationship will face much more challenge by structural unemployment which has occurred currently.