The strength of shear stress in position of source is calculated by the data of mid-small earthqudkes.The strength of str ess field or state of primary stress is also studied.

• 利用腾冲火山区中小地震地震波资料，计算得到的地震震源处剪应力强度值，对火山区应力场强度或初始应力状态进行了研究。