Since the bilateral commerce between the USA and China changes greatly and Chinese government continues to reform and delegate power in the economic field, it is of importance to study the Uniform Commercial Code of the USA. The study specifically studies the features of modal verbs in the UCC through the comparison with the United States Code and Frown. With the help of Antconc, the distribution of modal verbs, the modal value of the three sets of corpora are examined and (...) analyzed based on the theory of Halliday’s systemic-functional grammar. The results show that there are significant differences between the three sets of corpora and the three main features of modal verbs in the UCC are: the high frequency use of may, the relatively lower frequency use of legal modal verb shall, and the much higher frequency of must and may not. The seemingly contrary usages within the UCC are discussed and explained with the background of the legislation and the legal thoughts of the major legislator in a sociosemiotic approach. With both the quantitative and qualitative analysis combining the examples, the study hopes to shed light on the related legal translation and further enhance the understanding of the modal verbs in the UCC as well as legal discourse in a more general context. (shrink)