In this study, we introduce convergence technologies of agriculture and USN (Ubiquitous Sensor Network) technologies for collecting and controlling plant growing status according to microclimate around plants. In order to optimize the greenhouse cultivation environmental control, greenhouse operating system gathers greenhouse environment information from various sensors and provides appropriate control functions using various actuators. With this viewpoint, we develop greenhouse operating system using standard communication protocol, it can collect information and control microclimate effectively through several greenhouse control gateway. The developed greenhouse operating system controls automatically microclimate inside greenhouse based on farmer's experience. In the future, we expect that the proposed greenhouse operating system will be effective for collecting environment data of various types of greenhouse and the farmer can set different desired microclimate levels depending on certain conditions using greenhouse operating system.