This study was carried out in order to evaluate the physical properties of domestic kraft paper according to the changes of pre-conditioning environmental conditions. For the testing of physical and mechanical strength of paper, the specimens must be preconditioned under the specific environmental factors, such as temperature and RH. Recently, Korean Industrial Standard is revising for the coincidence with International Standard Organization. In this study, the physical and mechanical properties of kraft paper were considered by the two kinds of standard, KS M 7011 and ISO 187, and evaluated by the linear regression equation.