An apparatus and a method for reserved transmission of non-real-time content in a heterogeneous network environment are disclosed. According to the present disclosure, a method for performing reserved transmission of non-real-time content in a heterogeneous network environment comprises receiving a transmission reservation option from either a mobile terminal user or a server, collecting information on networks accessible by the mobile terminal and data transmission rate on a regular basis, performing scheduling of whether to transmit data over a currently accessible network, based on the received transmission reservation option and the collected information on the accessible networks and the data transmission rate, and repeating data transmission according to the scheduling until transmission of the content is completed.