A large worldwide effort to reconstruct the climates of the past millennia is now going on in the framework of the “Global Change” issue. One of the data types useful for this study is the historical climate information. China constitutes in this context a highly privileged region, as a large number of historical climate data covering several millennia are available there. Chinese scientists have carefully drawn this information from chronicles, official documents, scholar’s writings and local gazetteers. It is worthy comparing the above-mentioned climatic information with the information from first noninstrumental and later from instrumental meteorological observations carried out by Westerners in China. It will be shown how Westerners - some of them soldiers, others being part of a strong coherent group of Jesuit missionaries, still others scientists - carried out meteorological observations in China and that the information is nowadays most useful in the context of the “Global Change” research.