One powerful solution to improve the productivity of protected horticultural facilities is environmental control. Greenhouse equipment using information and communication technology (ICT) has been implemented in environmental control systems. From the 1960s to the 1970s, fundamental research and development of environmental control systems for greenhouses were actively conducted. Environmental control systems employing microprocessors and PCs began to be introduced in Japanese commercial greenhouses in the 1980s. However, by 2012, only 1.41 % of total Japanese greenhouse area employed such systems. To create a smart greenhouse that employed ICT, a ubiquitous environment control system (UECS) was developed for practical use in 2004. In a UECS, each environmental measurement and control device in the greenhouse (ventilation window motor, heating device, etc.) with an embedded microprocessor is called an autonomous decentralized unit (node). The nodes are connected with each other through the Ethernet (IEEE803.2), and they control environments in a coordinated manner. We reviewed the present situation and prospects of UECS.