Since July 1997, Hong Kong has become a Special Administrative Region (SAR) under the sovereignty of China. This paper compares the social well-being of Hong Kong residents before and after the change of sovereignty by analyzing six sets of survey data collected between 1990 and 2001. These are six biennial territory wide Social Indicator Surveys conducted to collect subjective assessments of well-being of Hong Kong residents. Analysis of the survey data which are typically categorized subjective evaluations has to deal with the commonly encountered problems of "direct quantification" (Schuessler and Fisher, 1985) and "incomplete data" (Little R. J. A. and Rubin D. B., 2002, Statistical Analysis with Missing data (Wiley-Interscience, New Jersey). The problems are handled by applying "optimal scaling" and "hot-deck imputation" as recommended by Shen S. M. and Lai Y. L. (2001, Social Indicators Research 55, pp. 121-166). Different life domain measures as well as compound measures in the form of indices are studied. The data analysis indicates that the residents of Hong Kong were most satisfied in 1997 and least satisfied in 1995. It reveals that the sovereignty change had major impact on many life domains of the people of Hong Kong and the effect was compounded by the economic situation of the territory.