The Macau social security system has been modified several times since it was established in March 1990. The reform measures include increasing coverage, expanding welfare and subsidy projects and raising old-age pension benefits. As its population structure changes, Macau, similar to most advanced countries, faces a bullet-shaped population distribution with a small population of elderly individuals and young children and a larger population of young adults. Currently, Macao’s population is characterized by low birth and mortality rates, an aging population and increasing life expectancy, all of which will create financial problems for the social security fund. To address these challenges, this thesis aims to estimate the future financial balance of the Macao social security fund based on an actuarial model and to analyze how old-age pension benefits and contributions may be adjusted to address the shortcomings of the existing old-age pension system, and thereby achieve a reasonable allocation of resources and reduce the government’s financial burden.