Abstract: For thousands of years, the Chinese society has been affected by its patriarchal system that has an everlasting and strong stand of "boy preference". This study examines the impact of old-age social security on the traditional birth preference of Chinese urban and rural residents. The data is based on the four-phase survey of CGSS2006, CGSS2010, CGSS2012 and CGSS2013. The regression results show that participation in basic social security pension scheme has significant effect on birth preference. In summary, old-age social security can,(1) change people's attitudes toward traditional fertility values such as having sons for "old age security" and "carry-on family name";(2) reduce insecurity and dependency about old age among urban residents;(3) improve the quality of daily life and resources for the elderly. However, due to the household registration segregation and the social security expenditure disparity between urban and rural areas, old age pension has less effect on the traditional birth preference of rural residents. This study provides new insights into the impact of social security on important traditional cultural values at individual levels with a comparison between urban and rural residents.

Key words: pension security, nurturing preference, urban-rural differences