Compared with the other life stages, the middle-aged generation stage is the stage that little research has focused on. However, previous literature and survey, both domestic and foreign, pointed out that the life satisfaction is the lowest for the middle-aged generation of all age levels. Therefore, the life of middle-aged generation certainly requires more concerns. This research focuses on the middle-aged generation’s family development stages, family structures, and life satisfaction. There are three purposes of this study: 1. To investigate the middle-aged generation’s life satisfaction conditions. 2. To understand their life satisfaction conditions in terms of different family development stages and family structures. 3. To analyse the effect of their family development stages and family structures on their life satisfaction. This study analyzes personal background as a control variable, family development stages and family structures as independent variables, life satisfaction as a dependent variable. A questionnaire survey was carried out in a convenience sample. Participants had to meet the requirements for target respondents: 40- to 60-years-old, married, having at least one living parent, and having at least one child at any age, living with spouse and children.Out of the 730 copies of questionnaires distributed, 499 copies were collected, 333 was effective.The results indicated that middle-aged generation is generally content with their life.Where family development stages are concerned, the adults at the first stage (the stage before families with school-aged children), the second stage (the stage of families with teenagers),and the third stage (the stage of families launching young adults) experience significantly lower life satisfaction, as compared with the middle-aged adults at the fourth stage (the stage after empty nest). Where family structures are concerned, middle-aged adults living in stem families or nuclear families do not show significant difference in life satisfaction. According to the results, suggestions about family development stage and family structures were provided for middle-aged adults, the government, schools, enterprises, family life educators, and etc., hoping to enhance the life satisfaction of middle-aged adults.