Since maritime commercial activity involves national boundary crossing, maritime law is never disconnected from international convention. Vessels that transport cargoes are the keys to maritime activities. Maritime lien in maritime law pinpoints the probability of liability and highlights the internationalization of cargo business. This paper discusses maritime lien by focusing on ROC maritime law. It analyzes claims secured by a maritime lien, their priority and valid period. The paper presents the differences between ROC maritime law and international convention and it makes suggestions regarding how to modify ROC maritime law.