A method of cell reselection for a mobile communication system comprises determining whether a mobile device in the mobile communication system is capable of initiating an emergency call through the second cell when a network of the mobile communication system restricts the mobile device from accessing a first cell, and the mobile device performs a first cell reselection procedure to switch the first cell to the second cell, so as to generate a first determination result, and determining whether the mobile device camps on the second cell according to the first determination result.