This paper links international demographic risk and pension fund management of TLPS (Taiwan Labor Pension Scheme). Population structure and average age are considered in Time Series models. It shows that the population structure would influence on the Taiwan’s excess stock return but not on MSCI World Index excess return. That means global investment can reduce the risk of the population structure. All of the investment strategies employed in this paper can not eliminate the population risk. Meanwhile, replacement ratios would be overvalued and guarantee cost would be undervalued as we pass over demographics. The impact of demographic risk is decreasing with the entry age. The guarantees from government help laborers to reduce demographic risk and raise the replacement ratio.