By using the expressions for the maximum absorption per wavelength (αλ),and the relaxation frequency ∫r of the boric acid relaxation derived previously by the author and employing the related oceanographic literatures,the effects of pressure,temperature,pH and salinity on (αλ)r and ∫r of the boric acid relaxation in sea water have been estimated.Results show that (αλ),not only increases with pH but also increases approximately linearly with pressure and temperature,and is nearly proportional to the 1.35 power of salinity.However,pressure,pH and salinity have negligible effect on ∫r; therefore,∫r,can be approximately expressed as a function of temperature only.Comparisons of the predicted with the measured (αλ)r and ∫r in different ocean areas are given.