Abstract: Mt. Wuyi, located at 27°37‛-27°54‛ N, 117°27‛-117°51‛ E, is the highest mountain in South-East China. Its main peak, Huanggangshan, is 2158 m above the sea level.  In 1955, P. C. Chen organized the first expedition to Mt. Wuyi, and the authors investigated the different ravines and the forests of that area in 1976 and from 1979 to 1984 respectively. Up to now 355 species of the bryophytes have been found in Mt. Wuyi.   I.  The influence of the factors of geological history on the bryoflora of Mt. Wuyi Fujian Province, belonging to Cathaysian, one of three Chinese ancient lands, was a part of ocean until the end of the lower Tertiary.  In the early Devonian, Fujian uplifted above the sea level, but it submerged in the sea later, and then uplifted above the sea level again in the upper Triassic. By the end of the lower Triassic the Himalayan movement influenced the paleogeography of China deeply, and the eastern and central mountains of Fujian uplifted again.  In the Ter- tiary, Fujian was influenced by the hot maritime weather, so the tropical evergreen forests existed in southern Fujian at that time.  The conclusion was made by Z. B. Zhao in 1983 after his long period of study on geological history of Fujian Province since the Yanshan movement.   According to the morden geographical distribution of Chinese bryophytes, it seems that the above influence might be related to the bryophytes of Mt. Wuyi and also the southern part of Zhejian Province.  By the end of the Tertiary the weather became cold in most parts of China. Since then the cold weather and hot weather alternated several times.  One kind of the ende- mic elements of the bryoflora formed in the area from the south-eastern coast of China to the southeastern Xizang (Tibet), including Japan.  They are not specialized at the family level or closely related to each other, but they have similar distribution and belong to different families.   In the Quaternary, Mt. Wuyi gradually uplifted following the Himalayan movement. As the weather cooled down in the upper part of the mountain,  deciduous  broad-leaved  and  needle- leaved trees increased there. Meanwhile, temperate genera and species of the bryophytes spread and invaded South China and entered Mr. Wuyi.  Rhytidiadelphus and Hvlocomium probably be- gan to grow in Mt.  Wuyi at that time, and their distribution is quite different from their pri- mary one.  On the other hand, a part of tropical and subtropical bryophytes might enjoy the changed weather and environment in the Quaternary and existed in a few small localities of Mt. Wuyi, and the genera Haplomitrium, Endotrichella and Floribundaria are probably their represen- tatives.  From the point of view of geological history we are now  living  in  the  interglacial period and the present natural conditions will last continuously, so they will steadily influence the bryoflora of Mt. Wuyi in a long period of time.   2.  Essential characteristics of the bryoflora in Mt. Wuyi   Due to the geographical position and the other factors of Mt. Wuyi the bryoflora is repre- sented by numerous tropical and subtropical elements (34.1%), but the East-Asiatic endemic ones  (79.2%) are characteristic of the bryoflora in Mt. Wuyi (Tab. 1).  The tropical and subtropical families of the bryophytes, found south of Changjiang (Yangtzi) River, are Haplomitriaceae (1  genus, 3 species), Porellaceae (2 genera, 8 species), Frullaniaceae (2 genera, 10 species), Lejeun-  eaceae (21 genera, 35 species), Trachypodaceae (3 genera, 4 species), Meteoriaceae (10 genera, 17 species), Neckeraceae (5 genera, 8 species) and Hookeriaceae (3 genera, 3 species).  The above  8 families, including 46 genera and 85 species, represent about 1/4 genera (24.3%) and less than  1/4 species (23.9%) of the bryoflora of Mt. Wuyi. Most species of East-Asiatic elements show very close relationships with Japan, and are  widely distributed from the low altitude of Mt.  Wuyi to the summit of Mt.  Huanggangshan.  However, the Holarctic species (26.8%) are also important elements of the bryoflora in Mt.  Wuyi, showing its transition nature, although it is located in the subtropics.  Moreover, the in-  fluence of the Himalayas also exists in Mt. Wuyi, and the Himalayan elements cover 14.4% in  the bryoflora of Mt. Wuyi.  The similarity coefficients between the bryofloras of Central and  South America, Africa and Oceania and that of Mt.  Wuyi are from 5.0-9.2% respectively. The  endemic species are not very many and cosmopolitan species are only 7 there. In 1958, P. C. Chen designated Mt. Wuyi as “the transition region of South and North  China rich in East-Asiatic genera and species”.  His very important conclusion is essentially in  accordance with the fact of the bryoflora on Mt. Wuyi.  Recently, some of the new records fur-  ther show the characteristics of the bryoflora in Wuyi.  Two facts are worth being mentioned.  One is that East-Asiatic genera are only five in Mt. Wuyi.  However, there are 9 East-Asiatic  genera in Mt. Huangshan more than in Mt. Wuyi; 4 East-Asiatic genera are recorded in Mt.  Shennongjia.  The other is that epiphyllous liverworts in Mt.  Wuyi, consisting of 7 families, 21  genera and 36 species, are less than on Hainan Island and Xishuangbannan, located in the tro-  pics in China.   3.  Comparison between the bryoflora of Mt. Wuyi and those of the neighbouring regions   As China covers a very large area, bryofloristic elements are quite different in the diffe-  rent regions.  In this section, we are concentrated on making a comparison between the bryof-  loras of Mt.  Wuyi and the regions belonging to the Central China of the bryoflora named by  P. C. Chen.   Huaping Forest Region, Guangxi Zhuang Autonomous Region in South China, with both