Climatological monthly mean variation of the surface heat flux for the gulf Bac Bo has been calculared using observational data from 1956 to 2006 by bulk method. The long-term annual mean net heat flux, averaged the gull Bac Bo, is 55 W/m² (positive sign means the sea gains heat from the air), and the seasonal variation ranges from a maximum of 146 W/m² in April to a minimum of -32 W/m² in December. The seasonal geographic distribution of the net heat flux is determined mostly by turbulent latent heat flux. In winter positive sign means the air gains heat from the sea.