This paper introduces the outline of damage and lessons learned from the 2005 Fukuokaken-Seihouoki (offshore) earthquake occurred on 20 March 2005. Firstly it is reported that damage coccentrated on (1) Genkai island, Shikanoshima, and northern tip of Itoshima peninsula, (2) port facilities and man made ground in Hakata Bay, and downtown of Fukuoka city.
The reason of these damages are discussed respectively as follows. (1) These area are located near from the epicenter, and the houses which were constructed on the cut/embankment ground had severe damage. (2) These damages are easily expected for the observed ground motion. (3) In irregular soil layers and concave layers, land ground motions were increased and damage of buildings and infrastructures in these area became severe.