The Zhalantun area of the eastern part of Inner Mongolia is located at the northern section of Greater Khingan seismic belt, and it has complicated geological structure with relatively dynamic moderate-strong earthquakes in history and modern times. Seismic activities in this district is selected as the research object. Based on the completeness analysis of seismic sequence in the district, least square method is used to conduct time scanning calculation of b values, and maximum likelihood method is used to conduct space scanning calculation of b values, b value during the scanning time is the mean b value of research zone in every scanning window, so its amplitude of variation is not quite great, with variation range within 0. 78 ~ 1. 13, and of error range within 0. 04~0. 065. Space scanning results indicate that the space distribution range of b values basically stays within 0. 4 ~1. 8, and error range within 0. 045~0. 085. Low b value zone is in the north central section of the Arun River breakage, with b value within 0. 5~0. 7, which indicates that the earth crust medium of this zone is under the state of high horizontal stress accumulation and it maybe the dangerous zone where moderate-strong earthquake might occur in the future.%内蒙古东部的扎兰屯地区位于大兴安岭地震带北段,区域地质构造复杂,历史及现代中强地震较为活跃.本文以该地区地震活动作为研究对象,在区域地震序列完整性分析基础上,用最小二乘法进行b值时间扫描计算,用最大似然法进行b值空间扫描计算.时间扫描中的b值为每个扫描窗口内研究区的平均b值,因此其变化幅度不大,b值变化范围基本维系在0.78～1.13,误差范围为0.04～0.065.空间扫描结果显示,扎兰屯地区b值空间分布范围基本维系在0.4～1.8,误差范围为0.045～0.085;低b值区域为阿伦河断裂中北段,b值大致分布在0.5～0.7,表明该区域地壳介质处于高水平应力积累状态,可能是未来发生中强以上地震的危险区域.
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