Under the framework of system-functional linguistics theory, this article researches some content of Rotterdam rules and Customs of the Peoples Republic of China. Through Antconc, a tool for concordance in corpus, this work compares and analyzes two legal texts in terms of modality, thematic structure and information structure, and concludes the differences in linguistic struc-ture between English and Chinese shipping conventions. On this basis, with the three principles of purpose, coherence and faithful-ness in functional theory, this work finds the functional approaches and strategies of legal and customs transport translation so as to provide some new perspectives for maritime convention translation.