Thermohaline fine structures are traditionally measured by ship-loaded instruments. This method has a high vertical resolution, but alimited horizontal resolution. The reflection seismic method, which is to study the physical oceanography, can effectively improve the horizontal resolution of thermohaline, so as to understand horizontal variation of thermohaline fine structure, and to provide high resolution basic data for researches in ocean and climatic change, which is called “Seismic Oceanography”. The recent progress in development and applications of seismic oceanography in the past  five years are summarized in the paper, mainly including observing oceanographic front , imagining water mass boundaries, analyzing ocean internal wave spectra and mesoscale eddies fine structure, as well as the full waveform inversion of reflection seismic data for ocean and amplitude-versus-offset analysis of acoustic reflections for temperature contrasts in the water column. The difference and relation among seismic oceanography, marine acoustical tomography and high frequency technology applying in the physical oceanography is discussed respectively. Future associated research may emphasize the relationship and quantitative analysis between seismic parameters and thermohaline physical model, seismic processing method for studying water column, application of the historical data of marine seismic integration and so on.