A method for monitoring paging messages in a mobile station with a subscriber identity card camping on a cell is provided. A paging message from the cell is monitored at a set of M predetermined time intervals. A first paging message with a first subscriber identity information being successively broadcasted in the paging channel at a Nth predetermined time interval and a (N+i)th predetermined time interval of the set of M predetermined time intervals is determined. A second paging message with a second subscriber identity information being successively broadcasted in the paging channel at the Nth predetermined time interval and a (N+j)th predetermined time interval of the set of M predetermined time intervals is determined, wherein j>i. The paging channel is monitored at a (N+i)th predetermined time interval and a (N+j)th predetermined time interval of following predetermined time intervals subsequent to the M predetermined time intervals.