The dc susceptibilities have been measured on cobalt stearate (CoSt2) Langmuir-Blodgett (LB) multilayer films. Two successive peaks and irreversibility are observed clearly in both parallel and perpendicular directions to the c axis. These behaviors are consistent with the mean-field theory for the Heisenberg-type spin-glass system having a weak single-ion anisotropy. The above behavior has never been observed in small CoSt2 particles, so it is considered to be an inherent characteristic in the LB film structure. The magnetic behaviors between CoSt2 LB films and other related compounds are compared and discussed.