The field experiment results of three prototypes of AWS are described.These prototypes submitted a tender and had been preliminary selected by CMA. The experiment shows that under normal conditions,the observing accuracy could basically meet the requirement of CIMO for AWS.Their average vaines for ten days and for a month have no obvious differences with manual observation. But the stations failue often appeared in operation. So that they cannot be used in professional work.The improved prototypes are being tested in field stations now.