Abstract: In the past 60 years, the China Research Institute of Radiowave Propagation（CRIRP） is specialized in tropospheric radio-duct over-the-horizon radio environment and propagation model and its application, which mainly include the tropospheric radio-duct mechanism and prediction method, atmospheric radio-duct detection, prediction and forecast method, ultra short wave or microwave trans-horizon propagation algorithm, beyond the horizon information assurance and verification evaluation of radio information system equipment, etc. This reflects the development history and latest research achievements of relevant technologies in the tropospheric radio-duct over-the-horizon propagation field, and the further practical application requirement and trend are proposed.