Abstract: Solitude referred to a state in which a person was alone and separated from others. It provided freedom to select one’s mental or physical activities. Contrast to the negative emotional experience of loneliness, solitude was a constructed state and was open to all emotional experiences. Self-reported scales and Experience Sampling Methods (ESM) were used to measured solitude. Research revealed, as the age increased, individual spent more time on solitude and had more positive attitude toward it. Evidences showed that solitude had positive effects on individuals’ mental health, creativity and enhanced self-integration. In the future, the structure of solitude required more research. Research should also pay attention to the developmental mechanism of solitude and cultural differences. The neural mechanism of solitude would be an important and valuable researching domain in the future.

Key words: solitude, loneliness, individual development, mental health, creativity, self-integration