The wind fields retrieved by scatterometers from GMF (Geographical Modelling Function) would be invalidated under rainy conditions, due to scattering and attenuation effects of rain drops. The scatterometer (HSCAT) and the scanning microwave radiometer (RM) onboard HY-2A can give observations over sea surface at the same time. In this paper, firstly, data of HSCAT and RM onboard HY-2A observing rainy ocean surface were selected as experiment data, with corresponding buoy wind fields. Secondly, an artificial neural network was established for wind fields retrieval under rain conditions, which was tested by other data sets.