A base station and a user equipment with enhanced PDCP duplication are provided. The base station generates at least one RRC message for a user equipment, wherein the at least one RRC message includes a set of multiple activation criteria, and each activation criterion corresponds to one of multiple RLC entities. The base station transmits the at least one RRC message to the user equipment. Multiple logical channels are provided in a MAC layer, each RLC entity corresponds to at least one of the logical channels, each RLC entity corresponds to a working status (activation or deactivation). At least one of the working statuses of the RLC entities is changed due to at least one of the activation criteria being satisfied, and the base station changes a transmission restriction of at least one specific logical channel among the logical channels based on the changed working statuses of the RLC entities.