An automatic microclimate observation system set up in a rice field is introduced. Its performance is evaluated in respect of the practicality, data arrival rate, and equipment reliability. The result shows that this system can provide timely and accurate microclimate information without delay. The data arrival rate is over 95% and the equipment reliability beyond 85% with a low proportion of format errors and abnormal records. Lightning disasters is the main factor influencing the stability and reliability of the system. Therefore, the practical advantage of this system is obvious in the field of agro meteorological research and services.