Safety of present food has been accepted on the basis of extensive use and experience for a long time. Many food resources have been developed by traditional techniques without any significant adverse impacts on the safety of food. Recently recombinant DNA techniques are being used to develop new food resources. These techniques enable developers to make specific genetic modifications in food resources that introduce substances that could not be introduced by traditional methods. With these techniques food resources are being to resist pests and disease, to tolerate herbicides, and to have improved characteristics for food preservation and nutritional contents. Because the properties of an organism result from interaction between biochemical pathways controlled by many genes, the genes conferring these traits usually encode directly responsible proteins for the new trait as well as proteins that indirectly modify carbohydrates or lipids in food. Therefore, this kind of food is regarded as new food that has not been existed before, and the safety of the food developed by recombinant DNA techniques should be evaluated upon scientific basis. In this paper, the issues upon safety of the food developed by gene manipulation are discussed in terms of composional changes that can be introduced, potential food safety harzards that might arise, present status of safety regulations in various countries and international organizations, and suggestions for the safety regulation in Korea.