Abstract: Xinjiang Uygur Autonomous Region covers an area of one sixth of Chinese territory,largest in area among all the province-level administrative regions of China.Xinjiang is situated in the hinterland of Eurasian continent and is under the control of a typical extratropical belt continental climate.Special geographic position and peculiar climate characteristic make algae resources very abundance in this region,but the research of algae flora is relatively weak.Diatom materials were collected from Xinjiang during the period of July to August,2001.Materials were obtained from a wide variety of habitats in the investigated area.In the field,samples were preserved with 4% formalin and kept in the Herbarium of the Biology Department of Shanghai Normal University.Microscope slides were prepared by acid digestion method and mounted in Canada balsam or Hyrax gum.Light microscope observations were conducted using a Nikon E800 DIC microscope at magnification×1000 and a Nikon digital cameral DXM1200.In the observation,five species and two varieties of Pinnularia(Bacillariophyta) are new records of China,They are Pinnularia halophila Krammer,P.obscuriformis Krammer,P.oriunda Krammer,P.reichardtii Krammer,P.substreptoraphe Krammer,P.substreptoraphe var.bornholmiana Krammer and P.viridiformis var.minor Krammer.The taxonomic characters and habitats of them were described.The study will provide basic data for algae resource investigation of China.