Abstract: In order to save water used for irrigation on urban green land, authors designed a control system of urban green land precision irrigation which was based on ATmega128 MCU, the embedded operating system, global system for mobile communications (GSM) and general packet radio service (GPRS). The system can detect soil moisture real-timely with the characteristics of network and intelligence of the system integrated functions such as historical data query, demonstrations of soil and irrigation information chart, generating different irrigation strategies according to the conditions of topography and vegetation. This system used the technology of switching SMS and GPRS automatically and adopted the embedded real-time operating system μC/OS, which further improved the reliability of the system. Precision irrigation can be realized by the detection of threshold of soil moisture and the plant physiological water requirement. Results in field show that the system has high reliability of data transmission and significant effects of water saving.