Fastanti, Fandri SofianaFitmawatiSofiyanti, Nery2016-11-152016-11-152016-11-15wahyu sari yenihttp://repository.unri.ac.id/xmlui/handle/123456789/8806Riau province has the largest peatland in Sumatra island, i.e. Giam Siak Kecil-Bukit Batu biosphere reserved. This area plays an important role for conservation due to its high biodiversity. One of the important flora occur in this region is moss. This lower plant groups can maintain the stability of micro climate. Research and publication of moss plants in this region has never been reported therefore the study of Bryophytes in this conserved area is important. This study aim to determine the family of moss plants from Giam Siak Kecil-Bukit Batu Biosphere Reserve. This study used exploration method. All of the samples were collected from three zones i.e. transition zone, buffer zone and core zone. A total of 17 moss families were recorded from study sites. 7 families of Marchantiophyta i.e Calypogeiaceae, Pallaviniaceae, Ricciaceae, Jungermaniaceae, Lepidoziaceae, Frullaniaceae, Lejeuneaceae and 10 families of Bryophyta i.e. Bryaceae, Dicranaceae, Sematophyllaceae, Calymperaceae, Fissidentaceae, Hookeriaceae, Hypnaceae, Leucobryaceae, Rhizogoniaceae and ThuidiaceaeenGiam Siak Kecil-Bukit Batu Biosphere ReserveexplorationmosspeatlandUR-Scientific Work Lecturer