An apparatus, system and method for forwarding user plane data. A user plane gateway (102) comprises: a receiving module (106) for receiving data which comes from a first network element (100) and uses a first transfer module; a converting module (108) for converting the transfer mode of the received data from the first transfer mode to a second transfer mode, wherein the first transfer mode is asynchronous transfer mode (ATM) and the second transfer mode is Internet Protocol (IP) transfer mode, or the first transfer mode is IP transfer mode and the second transfer mode is ATM; and a sending module (110) for sending the converted data to a second network element (104) using the second transfer mode. This apparatus, system and method achieve the effects that the aggregation of ATM network to the IP network, the networking device able to be compatible forwardly, improving bandwidth utilization rate, saving costs, etc.