181 species of high mountain bryophytes and lichens from Taiwan are examined. The floristic relationships of the high mountain mosses of Taiwan to its neighboring regions, such as Japan, Himalaya-Yunnan, Northeast China, Philippines and Borneo, are analyzed. The strongest affinity is found in between Taiwan and Japan. The reasons may probably be due to their having similar hyperoceanic island climate, their geographical positions on the same volcanic island arc chain, their being on the same route of monsoon, typhoon and the migratory birds which may act as carriers of moss disseminules (spores, gemmae and fragments) for long distance dispersal. In addition, this high similarity may infer that the Taiwan high mountains serve as the southernmost receptacle for Japanese mosses. The rate of immigration of the high mountain mosses of Taiwan is presumably estimated, approximately one species per 7,600 - 19,000 years on the average, since the upheaval of the central range of Taiwan in the later Pliocene. The moss flora of Indo-China Peninsula is not included in this study because of its being far from well-known, although it is very close to Taiwan in geographic distance, latitude, altitude, climate and forest type.