The need of customized home modification for the elderly is increasing and becomes more important. This study attempted to explore the effect of age-friendly customized home modification through the response of elderly residents. The target households were two very old elderly couples with chronic diseases. Three types of information were collected such as, first the characteristics of the modified features and the residents respectively, second the fit between them for each modified feature, and third the effectiveness of the entire modification through measures of life quality including perceived self-reliance and expectation of continuous residence and dwelling happiness. Interview and observation techniques along with a graphic scale to measure the residents’ responses were used. As results, highly positive responses to diverse dimensions of user benefits were identified for each changed feature of the houses, along with considerable improvement of the three aspects of life quality. It is significant in showing the rationality and importance of the customized modification to reach the ultimate aim of Aging In Place.