Abstract: In this paper, the well-known phenomena of the so-called high autumn clear weather in China is defined and the regions where it most frequently occurs are also determined. After analyzing the variation of 5-days" mean rainfall patterns, the dates of its onset and ending are then given. Mean-while, it is pointed out that these dates are also the dates of beginning of winter monsoon or retreatment of summer monsoon in the surface layer and onset of westerly jet-stream over SE-Asia or ending of the influence of summer monsoon in upper level respectively. Besides, in comparison the said weather with the Indian-summer in North America and old-women weather in Europe, it is found that there are some dissimilarities among them, especially the difference in the formation factors.