The committee for geotechnical investigation on the 2005 Fukuoka-ken Seiho-oki earthquake was organized on March 22, 2005, upon request of the Japanese Geotechnical Society. Since then, detailed investigation on geotechnical damages due to the earthquake has been carried out actively by the committee members, and useful geotechnical knowledge were obtained for the recovery and future earthquake. The contents of this paper are followed; 1) the committee's activity, 2) the damage of retaining wall with steep slope, 3) slope failure induce by the earthquake, 4) liquefaction-induced damages in the natural and reclaimed ground, 5) damage to port facilities, 6) damages to lifeline facilities, and 7) proposal for recovery and future earthquake.