HY2A isthe first Chinese marine dynamic environment satellite.It incorporates a radar altimeter to determine the sea surface height provided with high precision orbits as a reference.The DORIS DGXX receiver is onboard the satellite for delivering both Doppler range-rate and phase measurements.The VMSI software package is used to determine HY2A orbits,which can only process Doppler data but not the DORIS phase measurements directly.In this paper, we have proposed an efficient method of converting the phase data to the phase increment data.As the troposphere refraction is affected by the meteorological data,we have checked the reliability of DORIS (JIVB) meteorological data by comparing them with the data delivered by another set of sensors and results estimated from GPT2 model at JIUFENG station from June,2013 to September,2013.The comparison shows that the DORIS (JIVB) temperature and relative humidity measurements are inaccurate.Furthermore, we evaluate the impacts of inaccurate meteorological data on troposphere refraction and find it cannot be ignored.To minimize the impacts, a tropospheric refraction scale bias per pass is estimated in the orbit determination processing.Additionally, HY2A DORIS antenna z-offsets are given for three months to test the oscillator stability.The result shows that the DORIS oscillator on HY2A works well.Finally,we determine precise orbits based on3 months DORIS data.By comparing the results with the CNES orbits and checking with SLR measurements, our POD solutions satisfy the requirement of the HY2A mission.