In recent years, major countries are developing core technologies for Maritime Autonomous Surface Ships(MASS) and commercializing them after MASS trials. In the event of an unexpected accident during MASS trials, it is necessary to verify who is responsible and how to compensate for the damage. Firstly, in accordance with the 「Act on special cases concerning the regulation of regulation-free special zones and special economic zones for specialized regional development」, the trial entity is primarily responsible for personal injury and property damage resulting from an accident during MASS trials. In addition, in order to secure such liability for damages, it is stipulated that trial entity must provide a valid insurance certificate (Hull & Machinery and Protection & Indemnity). In the European Union, Belgium, and Finland, etc, it was confirmed that full responsibility for the trial was imposed on the trial entity, and the provision of hull insurance and liability insurance was made compulsory. In principle, the trial entity is responsible for, but it seems that the manufacturer can be held liable if damage is caused by a defect in the product. In other words, if damage occurs due to errors/defects in the automatic mooring system or remote control system, the manufacturer or developer of the system may be held responsible for the product if an accident occurs due to a predictable error. During MASS trials, accidents such as collisions may cause property damage, personal injury, and marine pollution damage to the trial ship and other ships. In case of property damage to the trial ship due to a collision, all of the damage are covered by the hull insurance. Property damage at the pier is basically covered by P&I insurance, and human injury and marine pollution damage are also basically covered by P&I insurance.