This study proposed a concept design of the cargo handling system for the pressurized liquid $CO_2$ carrier. The carrier was designed to transport a large amount of the captured $CO_2$ in liquid phase. The cargo containment system consisted of pressure vessels to withstand the elevated pressure condition. Employment of the piston gas enabled the pressurized liquid $CO_2$ to enter and leave the cargo vessels without phase change or evaporation of the cargo. If the temperature of cargo is lower than atmosphere, heat ingresses into cargo tanks caused by evaporation of liquid and pressure increases in tanks. Therefore, the onboard reliquefaction plant should be constructed. To protect the cargo containment system from the case of unexpected accidents such asa leak, and overpressure, safety systems are established to release the pressurized liquid cargo to the safety place immediately.