A method of cell reselection enhancement is proposed. A UE obtains parameters for extended cell reselection (ECR) in a mobile communication network. The UE goes to sleep and then wakes up periodically to monitor a paging channel. The UE either applies a normal paging cycle having a normal paging cycle length or applies a power-saving paging cycle having a very long paging cycle length. The UE performs cell selection if normal paging cycle is applied. The UE performs cell reselection based on the ECR parameters if the power-saving paging cycle is applied, and if the ECR parameters are still valid based on a list of conditions. In one novel aspect, the network provides the ECR parameters for a wider area for the UE such that the UE can still use cell reselection after waking up from a very long sleep to reduce power consumption.