We have investigated the structure and magnetic property of manganese stearate films prepared by Langmuir-Blodgett (LB) method. From the (00l) Bragg peak of the X-ray diffraction pattern, it is found that the films deposited on quartz substrates are Y-type LB film and Mn²⁺ ions in the film are arranged two-dimensionally with a lattice spacing of about 48.8 Å. The angular dependence of the (00l) Bragg peak intensity obtained from the structure factor of manganese stearate LB films calculated is consistent with the experimental data. Using SQUID magnetometry, the magnetic moment of the films was measured down to 1.7 K with applied magnetic field of 100 Oe perpendicular to the film surfaces. The susceptibility behaves according to the Curie-Weiss law in high temperature ranges and gradually deviates from the law below about 20 K. Comparing the magnetic moments measured at 1.7 K with two different applied magnetic fields perpendicular and parallel to the film surface, we observed magnetic anisotropy.