Automatic monitoring system based on robot total station is developed. Points to which attention should be paid in the developing of the automatic monitoring system and the control process are presented. The analysis on the layout of the monitoring network, the monitoring method and process, the system errors, the system components and the application of the technology show that: 1) In the monitoring of deep foundation pits with good visual conditions, monitoring by robot total station is feasible, which can reduce the cost and improve the monitoring efficiency. 2) In case the inclinometer is destroyed, robot total stations can be adopted to monitor the horizontal displacement of the foundation pit at different elevations. 