A new TMCP-manufactured high-toughness, low-temperature steel plate was developed for use in fabricating the cargo tank and hull structure of LPG carriers, which could offer both “the adequate performance in arresting the brittle unstable crack propagation in base metal” and “adequate toughness at the fusion line of welded joints produced by high-heat-input welding process.” This report reviews the concept followed in developing the high-toughness, low-temperature steel plate and the results of evaluation made of : (1) base metal crack propagation arrest performance, (2) fracture toughness at the fusion line of welded joint produced by high-heat-input welding process, (3) weldability, (4) cold-workability, and (5) line-heating workability. The above studies showed that the newly developed steel plate could ensure adequate safety and reliability for use in cargo tanks and hull structure of LPG carriers loaded with the cryogenic cargo, with a high level of crack propagation-arrest capability, excellent high-heat-input weldability, and shop workability.