To explore the relationship between interpersonal relationships and happiness of elderly for their happy old age, this study analyzes how the factors in sociology of population affect the elderly's interpersonal relationships and happiness. The ultimate purpose of this study is to look for practical alternatives that could improve the quality of life of the elderly. In order to examine the degree of daily interpersonal relationships and happiness of elderly men and women in a community, a non-probability sampling survey has been conducted at welfare centers and senior citizen centers in three districts in B city. The result showed that there is a difference in interpersonal relationships and feelings of happiness depending on the elderly's age, sex, job status, the presence or absence of a disease, leisure life, and whether they live with family or alone. Therefore, this study supports the successful life of Korean elderly by analyzing the factors related to their happiness, which will make a contribution to a healthy life of local communities. It is also designed to provide basic data for the elderly welfare practice plans that contributes to the quality of life of all Koreans by improving the interpersonal relationship and happiness of the elderly men and women.