Abstract
This study investigates the changes of thermal environment according to a change in temperature and humidity. In this paper we selected 5 kinds of ground cover plants and used empty chamber to ascertain the difference with plants and without plants. At the $28^{\circ}C$, Kentucky blue grass species showed $2.28^{\circ}C$ lower temperature than without plants. Especially Polytrichum commune showed $3.81^{\circ}C$, which is effective to maintain proper temperature on indoor environment. Under $18^{\circ}C$, Polytrichum commune decreased $0.1^{\circ}C\;{\cdot}\;min^{-1}$, Kentucky blue grass decreased $0.4^{\circ}C\;{\cdot}\;min^{-1}$. On setting temperature $28^{\circ}C$ it also showed similar tendency that the temperature decreased faster in the place without plants than the place with ground cover plants.