Abstract
Out daily life is being shifted into cyberspace along with the rapid progress of social network systems. This study examined quantitatively what people subconsciously conceive about city images by analyzing keywords found in "tweets" about a city. "Tweet" are affected by temporal conditions, such as some special events and different seasons when it is posted. Those fluctuations are taken into consideration in this study. Results show the following: 1) "tweet" quantity is explained by the degree of attractiveness, population, season, and event; 2 "tweet" contents related to a city differ among cities. A city's character is reflected in "tweets". Moreover, the appearance of reflection is extremely incisive, so it must be treated with caution.
