Abstract:The features of changes for agro climatic elements and agro climatic m atching types in Yunnan were investigated. On the basis of historical climatic d ata from observed stations, orthogonal expansion method was used to extract stap le components from 17 climatic factors for three periods amid anniversary denoti ng local agro climatic features. And hierarchical cluster method was employed t o divide agro climatic matching classes of Yunnan. As the results of this resea rch, the principal changes of agro climatic elements and annual agro climatic types were summarized by 7 principal components independent of each other and 6 annual agro climatic types. The research shows that there was a trend of climate warming during the principa l season of Yunnan agriculture among the recent 54 years and it has been reinfor ced since 1990s. On the other hand, the annual changes of precipitation and suns hine duration were more conspicuous than airtemperature; the amplitude of sunshine duration was at least equivalent to one of precipitation; the drought strength in spring was decreasing; successive rain ing and shortened sunshine duration have an aggravated trend. With the reinforce ment of climate warming since 1995, the precipitation in summer has a decreasing trend whilst the amplitude of sunshine duration is large. From 1954-2007, only the minority of years has the agro climatic type analogous to their previous ye ars. Moreover, there are only 2 agro climatic types mainly affecting Yunnan reg ion since 1995. And the dominating agro climatic type arisen since the end of l ast century did not occur in 1950s, 1960s and 1970s, which has distinctive clima tic traits. The effects of these climate changes on agriculture in Yunnan are wo rth paying close attention. This research is very helpful to evaluating climatic influence, predicting agricultural production and undertaking meteorological se rvices.