This study aimed to investigate various factors related to the changes that retired people perceived in their social network which forms the base of their lives and activities during retirement. A questionnaire of retired people between the age of 55 and 74 was conducted by mail. Responses numbering 2,981 (men: 2,680; women: 301) were received, and 44percent of the data was valid. Factor analysis indicated that the changes that retirees noticed in their social network after retirement can be divided into four categories: community activities, friendships, family relationships and general social interactions. Quantification Theory Type I clearly indicated that although the factors related to the changes perceived in the social network after retirement varied depending on the category, the changes noticed were generally strongly related to age, reemployment situation, standard of living, cohabitation with family members, and area of residence, as well as other factors such as the employment situation before retirement, including position, type of work, and size of corporation, or career-related factors, including level of education.
