Electron optical properties of magnetic immersed lenses are studied using curved axes theory with wide beam.Principal trajectory equations and paraxial trajectory equations are obtained and all of second-order aberration coefficients are derived by Mathematica.The second-order curved axes aberration of a magnetic immersed lens which has analytic axial field distribution is calculated and a dispersion graph of aperture aberration is also given.It is shown that aberration characteristic of immersed magnetic lenses is very particular.