A series of total loss of log carriers of G/T 4000 class which are engaged in EAST-SOUTH ASIAN route have been reported during the last decade. The casualties has been investigated in depth to draw the efficient means of safety. The results of this investigation, which are described in this paper, have been submitted to INTERNATIONAL MARITIME ORGANIZATION(IMO) by KOREAN GOVERNMENT in cooperation with the KOREAN REGISTER OF SHIPPING to request the revision of stability criteria of ship carrying timber deck cargoes.