Investigated the degree of loneliness and the structure of social network in the aged who live at an old man's home. One hundred eighty three aged above 65 years were interviewed concerning perception of loneliness and social network and background variables. Results showed that the score of loneliness was higher than it, which had been before examined for the aged who live alone. Loneliness was associated with the number of social supporters. The degree of loneliness was lower when subjects had many supporters. However, background variables (marital status, health status, activity level, etc.) were not related to loneliness.