Guilin's ground-based GNSS station cannot be fully exploited in Precipitable Water Vapor (PWV) monitoring,owing to its omission of meteorological sensors.Here we use the pressure and temperature data from ERA5 reanalysis as well as from Guilin's ground meteorological stations to retrieve the GNSS PWV,so as to evaluate the accuracy and applicability of ERA5 in GNSS PWV retrieval in Guilin.The results show that referenced with data of Guilin's 10 ground meteorological stations in 2017,the ERA5 data of surface pressure (annual bias:-0.35 hPa,annual RMSE:0.65 hPa) and temperature (annual bias:0.86 K,annual RMSE:1.66 K) are accurate enough for GNSS PWV retrieval.As for the GNSS PWV retrieval results,the ERA5 approach has an average bias of 0.17 mm and RMSE of 0.35 mm,which is well correlated and consistent with meteorological station approach.The above results validate the accuracy and applicability of ERA5 surface temperature and pressure products in GNSS PWV retrieval in Guilin,and provide reference for GNSS PWV retrieval and data selection in other regions.