Abstract The system proposed in this paper collects temperature of leaves and humidity on leaves of crop. As well as greenhouse environmental information such as temperature, humidity, etc. Crop diseases, especially, have deep relationship not only with indoor envi- ronmental factors but also with humidity lasting time on leaves and temperature of leaves. Accordingly,monitoringcropitselfisasimportantasmonitoringindoorenvironments.Using these collected greenhouse environmental data, indoor environments can be more effectively controlled, and monitoring crop itself can contribute to improve productivity and to prevent crops from damages by blight and harmful insects. In addition, it will be possible for farmers to do control plant growth through closely studying relationship between indoor environ- mental information and monitored information on crop itself. Collected data can be stored to database either in server installed in greenhouse or to remote server. It is made possi- ble to collect information and control effectively and automatically greenhouse in the site or from a remote place through web browser. System components are: temperature sensor,