Abstract：The family Polytrichaceae has 17 genera all over the world， There are 6 genera and 54 species in our country， and there are 4 genera and 12 species of them in Xinjiang. The Atrichum has 20 species in the world ，there are 6 species and 1 variety in our country.By using scanning electron microscopy (SEM) of Polytrichaceae spores and peristome micro morphological observation， by hand sectioning on the leaf， stem cutting and under optical microscope to observe the structure and photography， and other kinds of comparison found that collected from the Tekas County and Tukkuztara County of Xinjiang Tianshan 3 specimens with different characteristics， and are compared with the literature found its characteristics consistent with the referenece of [Atrichum rhystopphyllum(Müll. Hal.) Par.] ，and it determined for Atrichum .The main feature of Atrichum is the leaf ventral segment 4～6 column， most of 2～5 cells. The study of Atrichum rhystopphyllum is new to Xinjiang. The study is provide Morphological descriptions and illustrations for Atrichum . The key to the Xinjiang genera of Polytrichaceae was also given； Do the results offerd new references to Polytrichaceae in Xinjiang.
