中文摘要：

利用地磁场CHAOS-5模型，计算和分析了1997年以来中国大陆地区的地磁长期变化．通过年变率及其等变线图、特殊等变线随时间的变化、长期加速度分布等，探讨地磁场长期变化的时空特点．计算中国12个站点的长期变化，分析不同站点的时间变化规律．结果表明，1997-2015年间，中国大陆地区地磁非偶极场的长期变化缓慢，各地磁要素的漂移方向不同．不同站点的长期变化差别较大，同一站点不同要素的长期变化并不同步．长期加速度分布不均匀，变化量小，增加或减小的区域清晰可辨．

英文摘要：

Using CHAOS-5 model of geomagnetic field , this paper has calculated and analyzed the geomag-netic secular variation in China since 1997.The temporal and spatial characteristics of the change of the geomag-netic field are discussed by the annual change rate and its contour map, the change of the special isochronous linewith time and the long-term acceleration distribution, etc.The annual variation ratio curve of 12 stations in Chinahas been calculated and the time variation of different stations has been analyzed.The result shows that the secularvariation of geomagnetic non-dipole field in the mainland of China has a long-term slow change from 1997 to2015. Secular variation at different stations are different, and the long-term changes of different factors at the samestation are not synchronous. Secular acceleration distribution is not uniform, the amount of change is small, but canclearly show the increase or decrease of the area.