This study aims to identify the degree of heat island in summer in Gwangju. For the purpose the city was classified according to use and surface components and temperature of the city for 24 hours was measured. The period of measurement was from August 11 to 13. 2003(two days). As a result of the measurement, the daily standard temperature of the central business areas and downtown areas was about $26^{circ}C$. That of new residential areas neighboring the downtown was $25.1^{circ}C$, and that of the outer residential areas was $23.4^{circ}C$. In comparison with the result that temperatures of the Gwangju University playground and the Gwangju Weather Bureau were $23.1^{circ}C$ and $23.3^{circ}C$ respectively, the temperature of the downtown was about $2.7^{circ}C$ Higher and that of the new residential area in downtown was about $1.8^{circ}C$ higher. And it was demonstrated that the downtown outer road under Mt. Mudeung is a low-temperature zone. When temperature of the city was measured based on surface components, the daily standard temperature of Gwangju Stream Bok-gae area was the highest, $24.2^{circ}C$, followed by $23.6^{circ}C$ of the downtown stream and $22.2^{circ}C$ of the greens (city park) and the waterside area.