In the present study, rotational hysteresis loss analysis is carried out for cocrra, and CoCrPt thin film media to evaluate the influence of microstructure on coercive force through the measurement of magnetic anisotropy. In each media, the magnitudes of defined as a magnetic field where rotational hysteresis loss diminishes remain almost a constant value of the values of coercive force. With increasing coercive force, the of coercive force gradually becomes smaller than that of switching field of magnetization by torque analysis. Through the analysis and it is suggested that the coercive force In each media is strongly dependent on the degree of intergranular exchange coupling and/or interactions. While, in and CoCrPt coercive force has a dependence on rotational hysteresis integral however, in CoCrTa films, any correlation between was not observed.