Recently, orthodontic anchor-screws have been widely used as anchorage units in orthodontic treatment. The present study investigated the stability of orthodontic anchor-screw fixation into bone based on a pull-out test and numerical analysis using a finite element method（FEM）．Furthermore, the effects of the anchor-screw insertion angle and cortical bone thickness on the stress distribution within the surrounding bone were investigated. From experimental results obtained by a pull-out test of anchor-screws implanted in an artificial bone model, the maximum pull-out load of anchor-screws with vertical insertion（angle of 0°）was higher than that of anchor-screws with angled insertion（angle of 45°）．Stress analysis using FEM showed that the maximum von Mises equivalent stress existed in cortical bone near the inserted anchor-screw when an orthodontic force of 2 N was applied in a horizontal direction. Moreover, such maximum stress in cortical bone increased with increasing the anchor-screw insertion angle. However, it decreased with increasing the thickness of cortical bone at all anchor-screw insertion angles.