Labor force participation level is important for labor supply and economic growth．Since changing age structure influences the overall labor force participation rate ( LFPR ) ，population ageing plays an important role in explaining differences in LFPR．By comparing age-standardized LFPR among China，Brazil，France，India，Japan and The U. S．，it is found that LFPR level of a young population is considerably higher than that of an older population under the same age-specific LFPR．Using the decomposition method of differences between rates，it is found that in 2013，the LFPR difference between China and Japan is at 12． 1 percentage points，of which 79． 0% is contributed by their age structure difference．Further empirical analysis through both national and international panel data models also indicate that LFPR is significantly negative related to population ageing．