This paper investigates the influence of city scale on employment using data from China. Probit models of employment determination are estimated. The historical population growth during China's planned economy, when migration was directed by the government and voluntary location choice was prohibited, is used as the instrumental variable of current population size. Instrumental variables estimates show that it is more likely for individuals to gain employment in big cities. A 1 percent increase in city scale increases one's employment probability by between 0.044 and 0.050 percentage points. Moreover, the scale advantage of big cities is heterogeneous among individuals with different levels of human capital, with the least-skilled workers benefiting the most.