Disclosed is an insertion assembly for door and window frames which comprises a side frame and a transverse frame which is perpendicular to the side frame. An L-shape fixed member is provided at the outside of a connection portion of the side frame and the transverse frame, a side fastening bolt is provided to pass through a through hole at an upright portion of the fixed member and a through hole at the side frame to connect a side fastening panel, and a transverse fastening bolt is provided passing through a through hole at a transverse portion of the fixed member and a through hole at the transverse frame to connect a transverse panel.