Zhang Shuai，Shi Chunxiang，Liang Xiao，Jia Binghao，Wu Jie
Due to the unique function that snow played in modulating energy and water exchanges in climate and hydrology system，it is important to estimate snow distribution and produce high quality products for short-term climate prediction and water resources management.National Satellite Meteorological Center publics FY-3 snow cover fraction product since 2009.It is necessary to evaluate the snow cover fraction product in order to verify the precision of retrieval algorithms and provide an objective evidences for climate studies.based on MODIS MOD10C1(MYD10C1) Global Daily Snow Cover Dataset，we carries out an evaluate of FY-3 snow cover fraction product from 2010 to 2014 based on five examine indexes，and analyses the bias distribution of snow cover fraction product in different time scales further.It is concluded that FY-3 snow product is a better time space consistency with MODIS MOD10C1(MYD10C1).For example，the consistency of two products is better in snow accumulation period，while it is reducing influenced by cloud detectionin snow melting time.At the same time，bias of snow cover fraction products have obviously changes in inter-annual time，seasonal and monthly.compares to MODIS products，FY-3 snow product is higher in North China，but it coverts to lower in whole China since 2012.Bias of two products decreases from snow accumulation period to snow melt period.In monthly time scale，North eastern China and north of Sinkiang area is sensitive area of snow variation.Bias is more stable because of Tibet Plateau is influenced by topography and covered with snow all the year.
