A statistic model for an interacting system has been developed to study the
thermal stability of the longitudinal thin film media. It has been found t
hat the magnetic interactions in the media have significant impacts on the
thermal assisted magnetization decay process. The decay rate increases as i
nteractions become stronger. However, exchange coupling delays the onset ti
me for fast decay, thereby improving the media thermal stability. The effec
ts of media orientation and grain size distribution have also been investig
ated.