Il contributo di de Ursis alla diffusione dell'astronomia occidentale nella Cina dei Ming

The transmission of European astronomical knowledge at the end of XVI century to Chinese elites has been one of the critical factors of the evangelization process applied by the Jesuits in China. Sabatino de Ursis, first collaborator of Matteo Ricci in Beijing and after his death his substitute, has been one of the first Jesuits to contribute to this transmission proving how the Western mathematical and astronomical knowledge was more advanced than the methods used by the Chinese astronomers to predict astronomical phenomena. With him the process of penetration of the Jesuits in the Imperial astronomical office for the calendar has started and later the Jesuits were appointed directors of this office from the mid of the XVII century until the end of XVIII century. In my contribution I will present the information about de Ursis' astronomical activity and the works he dictated to be translated in Chinese, with consideration of his role in the more general context of the astronomical activity of the Jesuits in China.