整理本台记录的地震500个，震中距从100km到160°范围，震中分布在本台四象限。逐一对每个地震分析定位，将本台定位结果和中国地震台网中心的定位结果对比，统计出平均偏差率。再详细计算本台及三个子台的四象限定位结果偏差率，对发生方位偏差的震中位置进行归类研究，寻找规律。发现主要原因是远震定位结果受台基噪声影响很大，近震定位结果受地质构造中断层影响很大。在日常工作中应用方位角法定位可以最大限度的增加定位准确度，近地震速报时注意肃南区域方位异常的偏差角度，为防震减灾工作提供较为准确的地震参数。

 Using 500 earthquakes recorded by JiaYuGuan seismic station.which epicenter distance range from 100 kmto 100 degrees and the epicenter distribution is in four quadrant.and these event were relocated .then this location results were compared with the USGS’s results.the results analyzed shows that the most azimuth deviation abnormal is form south-eastern for teleseismic ,the main reason is due to the low signal-to-noise ratio.the local earthquake’results  show that the azimuth deviation abnormal is form south-eastern too.especially SuNan Earthquakes,.we analyzed the geological structure in this region.our results suggest that the azimuth deviation abnormal main reason is due to earthquake ray was reflected(or refracted) cluste inhomogeneity.this result is benefits for precise earthquake location in JaYuGan station.