Global Navigation Satellite System(GNSS) radio occultation measurements have been assimilated into the fourdimensional variational data assimilation system(YH4DVAR) using a one-dimensional bending angle operator(GBAO)as a new type of observation. For the sake of verifying the impact of GNSS radio occultation(RO) measurements to the data assimilation system, three experiments have been conducted. The statistical results of the analysis error experiment and forecast skill experiment show that the GNSS RO measurements have an impact on the analysis system. The typhoon forecast experiment shows the impact on the important weather process. They all have a positive impact on the weather forecast. Lastly, we look forward to future work on the observation system simulation experiment(OSSE) to investigate the impact of GNSS RO measurements as a function of observation number, which is an effective method to estimate the saturation of the observation number. Global Navigation Satellite System (GNSS) radio occultation measurements have been assimilated into the fourdimensional variational data assimilation system (YH4DVAR) using a one-dimensional bending angle operator (GBAO) as a new type of observation. For the sake of verifying the impact of GNSS The statistical results of the analysis error experiment and forecast skill experiment show that the GNSS RO measurements have an impact on the analysis system. The typhoon forecast experiment shows the They all have a positive impact on the weather forecast. Lastly, we look forward to future work on the observation system simulation experiment (OSSE) to investigate the impact of GNSS RO measurements as a function of observation number, which is an effective method to estimate the saturation of the observation number.