Role of plant factory with artificial light (PF) in urban areas is discussed.Importance of fresh food production in urban areas is emphasized with respect to resource saving,environment conservation,losses of quality and quantity of produce during transportation and community communication.Concepts of closed plant production system and resource use efficiency are introduced to discuss the resource saving characteristics of PF.Annual productivity per land of PF is compared with that in the open field.PF can be a key technology of urban agriculture in the forthcoming decades.A trial project of networks of PF is introduced.