Statistics from the Ministry of the Interior showed that unmarried and divorce rate are both increasing year by year. The reasons of postponing marriage and not getting married are quite complicated because of extension of national compulsory education, improvement of feminine economic capability, and the joining of foreign spouses to the marital market. These cause the unbalanced marriage market even worse; thus, lots of people choose to postpone or decide not to get married. To establish a family is a general life norm. However, unmarried people who are old enough to marry often face negative image. Do unmarried persons satisfy with their single life? Therefore, the primary purpose of this study was to understand life satisfaction of unmarried persons, to investigate the difference of life satisfaction on selected personal characteristics, and to explore predictors of life satisfaction. Based on survey method, the target population was unmarried persons including never married, divorced and widowed aged from 25 to 55. Through purposive and snowball sampling, 459 usable questionnaires were returned. Two instruments were used: Life Satisfaction Scale for Unmarried Persons, and Personal Background Questionnaire. Data were analyzed by descriptive statistics; t-test, One-way ANOVA, Scheffe method, and multiple regression by using enter method. The results were as follows: (1) Unmarried persons' level of life satisfaction was above moderate level; (2) There were significant differences of unmarried persons' life satisfaction on gender, age, marital experience, types of singles, type of occupation, and monthly income; (3) Four factors predicted unmarried persons' life satisfaction for 11.6% variance including age, other type of occupation, monthly income above NTD 50,001, and types of singles as ”Regretfuls”. Based on research findings, recommendations were provided for unmarried people.