The purpose of this study is to find out potential factors associated with the quality of life in South Korean senior people, on the basis of their oral health, so that it may provide basic reference materials in developing and assessing national policies for improving the quality of life in senior people. The data of 3,882 senior citizens who were at the Western age of 65 and up and got a dental checkup were selected from the first-, second- and third-year raw data of the 4th National Health and Nutrition Survey that were conducted from July 2007 to December 2009. And the statistical package SPSS 19.0 was employed to analyze the selected data. The findings of the study were as follows: The senior citizens whose remaining tooth was larger in number and who didn't need partial or full denture lead a better quality of life. Therefore, dental loss without any prosthetic appliance has significant negative effects on the quality of life in senior people, so it is urgently demanded to try to increase the number of remaining teeth and apply dental prosthesis to senior people for recovery of their oral health.