Small modular reactors (SMRs) have been an important international R&D activity because of their inherent safety features, modular construction approach and wide application perspectives. Compared with large scale nuclear power plants (e.g. 1000MWe light water reactor units), the economic performance of SMRs will be more sensible to outside constraints. It is especially the case for SMRs located in the very vicinity of the potential users. One of the possible constraints involves nuclear emergency preparedness and response. It would be very beneficial to the economic performance and the public acceptance towards SMRs if the plume emergency planning zones of them could be limited to their site boundaries. In fact, many concepts of SMRs have put this as one of their important design goals. Considering the factors in emergency planning, it would be currently not feasible to eliminate off-site emergency preparedness. However, it has been an international consensus that emergency planning could be simplified. For example, the emergency planning zones for SMRs may be significantly smaller than that for large scale light water nuclear power plants. This paper describes the current status of international R&D activities in the field of SMRs. The concepts and approaches governing the emergency planning in support of large light water reactors and SMRs are discussed. Relevant discussions and practice concerning simplification of emergency preparedness for SMRs are also briefly presented.