||Declining fertility and increasing longevity have brought about remarkable shifts in the age structure of the population. Europe, Northern America and Australia/New Zealand initially experienced one of such inevitable demographic events, that is population aging. While the transition from the young-age population to the aging population occurred over a much longer period in the West, the speed of aging is much faster in low-fertility countries of Asia. This has now emerged as a new issue challenging many low-fertility countries in Asia, as it has implications for the family and caring for the older persons. This paper provides a general overview of the fertility transition in Asia and factors affecting the fertility decline. Focusing on low-fertility countries in Asia, the paper highlights the implications of low fertility on population aging. Various indicators of population aging, such as the changes in age structure, potential support ratio and feminization of the elderly population, are presented for a better understanding of the overall situation. Comparisons are made with Europe, Northern America and Australia/New Zealand to put forward the magnitude of the challenge. As the Asian region contains over 60 percents of the global population and has experienced a rapid decline in fertility, the absolute size of the older population is a major concern. While the overall population growth rate has been declining over time, the number of older persons is increasing at a rate at least twice as high. In addition to the increase in older persons, a gender disparity in the improvements in the life expectancy at birth is likely to be illiterate and living in poverty. Providing family support, health care and financial security are some of the contentious issues aging societies will face. There have been discussions concerning the possibility of increasing fertility in countries with below replacement fertility. It is, therefore, crucial for governments to plan for an aging society long before fertility reaches a very low level. Meanwhile, it is important for Asian countries to recognize the significance of aging problems and start formulating policies for the elderly given that it takes several decades for government old-age pension insurance schemes to mature and operate at full scale. It would be more difficult for families to care for their older members because families would be smaller, people would live longer and the migration of young adults would mean that families would fragment. the present trends present a major challenge to address the needs of families. It is, therefore, important to consider the present trends in designing social policies, put the family at the centre of any future social policy development and examine good national practices when designing a new approach to family policies.