Abstract: Closed plant factories using artificial lighting will be extended commercially because of the large-scale requirements of the transplants or plant such as vegetables, forest tree, medicinal herb, and spice plant in the 21^st century. In order to research the optimal environmental control and electronic consumption accounting in the closed plant factories, a web-based environmental control system was developed using MS SQL Server 2000 and Visual Basic 6.0. The control strategy and control targets can be adjusted by end-user in local or remote areas via any browsers and the controlled equipment can be adjusted or improved easily with different levels of system security. All control variables and measured environmental data and plant images are monitored dynamically using web-server-embedded technology. The environmental control and electric consumption accounting were carried out in a pilot-type closed plant factory operated for two years in China Agricultural University.