Deterioration ofconcrete structure is caused by mass transfbr with mo 正 sture 」 n order to predict tho service life ot ' cencrete structures quantitative 且 y , it is necessary to clarify the mechanism of deterioration of concrete and reinforcement at exposure state fセom the viewpoint of moisture movement affected by environmental condition . Especially rainfall may cause wa 匸 eT penetration heavily and deeply in a liquid state and leads to more significant changes efwater content in ¢ onerete than a proeess in a vapor state 、 In this paper the effects of a cover roof and a crack in concrete on the moisture movemcnt were investigated experimentaliy using specimens embedding humidity sensors and electrodes . Experirnental res ults showed that water penetrated more deeply in uncracked concrete with higher water − to − eement ratie but water content did not change in the deeper part重 h跏 5cm . In Gase ofcracked concrete the wider crack caused fast ¢ 匸 and deeper water penetration , and the water content in the deep part increased before the saturation ofsurface part in the concrete wiIh lower water − to − cement ratio、 The change of relative humidity in the concrete due to temperature change showed different trends depending on the humidity in the pore. Kaywortts・