Abstract: A return radiosonde trajectory forecast method based on high resolution numerical weather prediction modeling is proposed in this paper. The trajectory forecast method is intended to be used for simulating the return radiosonde network observations and supporting evaluations of the observation impacts on numerical weather predictions. Meanwhile, the trajectory forecast system will also in plan to be used for supporting the return radiosonde application in target observation experiments in the future. A return radiosonde trajectory forecast system is established by embedding return radiosonde’s trajectory equations of ascent stage, drift stage and descend stage into numerical weather prediction model GRAPES (Global/Regional Analysis and PrEdiction System), a regional model with a 3 km horizontal resolution. A dynamic equation of parachutes in descend stage is also considered in this system. By using the trajectory prediction system, the preliminary test of the return sounding trajectory prediction is carried out for 63 successful real observations of return radiosondes. The results show that the forecast trajectories using this trajectory forecast system are reasonable and reliable, with the average error of track prediction less than 40 km in 6 hours.