Abstract: Based on the observed data of 16 meteorological stations in Hulun Buir from 1981 to 2019,combining statistical approach,the regional applicability of ERA5-Land and MERRA2reanalysis data including monthly temperature and precipitation were assessed.The results showed that reanalysis temperature and precipitation data of ERA5-Land and MERRA2 had a high relativity,low error and high applicability,comparing with observed data.However,underestimation and overestimation were also found for reanalysis data.The monthly temperature data of ERA5-Land was better than MERRA2,while the monthly precipitation data was reversed.In addition,the annual precipitation of ERA5-Land was obviously underestimated after 2005,which mainly appeared from June to August.Therefore,the corrections of systematic deviation were needed before using the reanalysis data to improve its applicability.