The 1993 Kushiro-oki Earthquake brought great damage to ports and harbours along the Pacific coast of Hokkaido, especially to Kushiro Port. In this research, the economical damage at Kushiro Port due to this earthquake was investigated based on interview and uestionnaires. Based on the results, economical rationality of countermeasures against liquefaction are investigated using cost-benefit analysis. Results of this study is summerized as follows.
1. The economical damage at Kushiro Port due to the 1993 Kushiro-oki Earthquake was at least 250,902,000 Japanese Yen including 60,000,000 Yen for port dependent industries and 190,902,000 Yen for port related industries.
2. Even when the damage to the quaywall itself is slight, the damage to stevedoring facilities tends to bring economcal damages.
3. In general, economical rationality of countermeasures against liquefaction was recognized for the facilities at Kushiro port.