This study investigated emission rate and emission amount of DEHP from building materials under varying adsorption area and emission area. For first experiment, the silica wool that imitated the house dust was hung in micro chamber to study variation of adsorption to house dust. Second experiment using glass plates as adsorption materials was conducted to understand variation of emission rate (EF) by ratio of between emission area of test specimen and adsorption area. Result of first experiment showed desorption of amounts depending on mass of silica wool were increased, except only one conditions. If this phenomenon similarly with experiment exist in house dust, human exposure of DEHP would be depended on the amount of house dust. Second experiment showed that EF tended to remain unchanged when ratio of emission area and adsorption area was increased.