A model for retrieval of wind stress and drag coefficient on the sea surface with the data measured by spaceborne synthetic aperture radar (SAR) has been developed based on the SAR imaging mechanisms of ocean surface capillary waves and short gravity waves. This model consists of radiometric calibration, wind speed retrieval and wind stress and drag coefficient calculation. A Radarsat SAR image has been used to calculate wind stress and drag coefficient. Good results have been achieved. A model for retrieval of wind stress and drag coefficient on the sea surface with the data measured by spaceborne synthetic aperture radar (SAR) has been developed based on the SAR imaging mechanisms of ocean surface capillary waves and short gravity waves. This model consists of radiometric calibration, wind speed retrieval and wind stress and drag coefficient calculation. A Radarsat SAR image has been used to calculate wind stress and drag coefficient. Good results have been achieved.