Abstract: In order to acquire the real-time data in the greenhouses, a voice warning system was developed. It can deliver the real-time data received from the sensors placed in the greenhouses like human voices. The whole system uses MS51 series monolithic processor as the master control unit, which deals with the input and output voice data stored in the ISD processor. And a control algorithm is also given to make the voices in accordance with the human habits. It has been proved that the system has the voice warning function and it also has the characteristics of easy control, simple interface and strong extension etc.