The basic features,extracting method of anomaly information and prediction significance for the group anomaly from the measurement data of 8 cross-fault short baseline at Lijiang,Yongsheng,Xiaguan and Jianchuan survey points in northwest Yannan Province,from 1984 to 2002,are studied. The results show that the group anomalys is a short-term prediction index for grouped strong earthquakes in the region with clear physical sense and high corresponding probability.