During late Ming and early Qing dynasties, Western Missionaries not only introduced new religion, science and western culture into China, but also changed the meanings of some Chinese terms. Although missionaries used Confucian terms, they brought new meanings to these terms by redefining and reinterpreting them, and they gradually became the exclusive terms of Catholicism. With the case study on the Sheng (Holy) and related terms, this article tries to explore Catholic discourses on the term Sheng and its semantic changes during late Ming and early Qing. It firstly illustrates the tradition of saints' worship in western Christianity. Then it discusses the semantic changes of Sheng in Chinese since pre-Qing period. It focuses on the reinterpretation of the Sheng and related terms in Catholic texts and the response to them by anti-Catholicism. The change of meaning of the Chinese character Sheng and the formation of Catholic terms related to it, could be regarded as a typical case of new ideas which were introduced and explained by missionaries in late Ming and early Qing.