Abstract: This paper discusses the origin center and the evolution center of the Cathaysian Flora. The authors discover that there are different evolution centers in different geological ages in China, and discuss their moving line through different geological ages. By analysing the anatomic stmcture of the fossil plants of Lycopods and Cordaitales, the authors suggest that the main mechanics of the origination and the evoluion of Cathaysian Flora is the result of the different tochastic dominances in adaptation to the external environments and the geographical separation and isolately developing from the Euramerican Flora. In this paper, the authors also make some works on statistics by counting up the number of the genus, species, extincted species, newly increased species, the percentage ratio of the newly increased species in different geological ages and discover that the Cathaysian Flora happened 8 time extinction events during its exisfing period in Carboniferous and Permian (88 Ma). In average, there happened 1 time extinction event per 11 Ma. Most of the extinction events happened periodically. Among them, 4 extinction events with smaller extinctional percentage ratio,can be called as normal extinction or background extinction, their extinction percentage ratio only reached up to 10.3% -16.2%. 2 of the 8 extinction events were larger, their percentage ratio of extinction reached up to 50%-60%, that refleeted the larger renewal and replacement of the composition of Cathaysian Flora. The rest 2 events happened at the boundary line of late and early Permian and at the end of Pemaian were serious. The former is a nonperiodical extinction event that might be related to the climate into arid changing in the world. In South China and in North China the percentage ratio of extinction reached up to 62% and 90% separately. Cathaysian Flora extincted totally at the end of Permian. As to the mechanics of the total extinction of Cathaysian Flora, the authors suggest that the Cathaysian Flora had become into a powerless stage before the big evironment changing happened in the late Late Permian, especially at the end of Permian. Besides, there happened series of the terrestrial events, such as, at the turn of Permian-Triassic period widely distributed the volcanic activities, and it is very possible that there abruptly happened an extraterrestrial event, certain celestrial bodies collided the earth accidently that stirred up and improved the total extinction of Cathayrion Flora.