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利用云南保山地震台记录到的 2001 年施甸地震数字化波形观测资料，根据尾波散射理论，测量了震源区尾波 Qc( f )值，结果表明，中心频率为 1.5 Hz 时，施甸地区尾波振幅衰减率 β(f ) 值在?0.012～?0.02 范围内，平均值为?0.017，Qc值在 110～140 之间，平均值为 124；得到施甸地区尾波 Qc值与频率的关系为 Qc( f ) = 77f 0.75 ；尾波波源因子 A0( f )与地震震级成正比，满足关系 lg A0( f ) = 0.899ML + 0.81，与频率成反比，满足关系 lg A0 = ?0.046 × f + 2.84 ；本文得到的一个重要结果是，施甸 5.3 级地震的最大强余震发生之前，Qc值存在一个变化过程；Qc值在均值附近 ±1.5 倍方差线内均匀地波动→Qc 值逐渐下降→Qc 值出现低于方差线的异常点→Qc 值逐渐恢复到正常水平→发震；施甸地区的尾波 Qc值不同于构造活动较为稳定的地区，而与构造活跃、地震活动频繁的地区较为接近，属于低频低 Qc值地区。
Based on the observation data of the 2001 Shidian seismic waveforms recorded by the Baoshan seismic station in Yunnan Province, the Qc (f) values of the coda in the source region were measured based on the coda wave scattering theory. The results show that when the center frequency is 1.5 Hz, The value of β (f) decay rate is within the range of 0.012 ~ 0.02, the average is 0.017, the Qc value is between 110 and 140, the average is 124. The relationship between the Q value and the frequency of coda in Shidian area is obtained For the Qc (f) = 77f 0.75; coda wave source factor A0 (f) is proportional to the magnitude of the earthquake, to meet the relationship lg A0 (f) = 0.899ML +0.81, inversely proportional to the frequency, to meet the relationship lg A0 =? 0.046 × f + 2.84. An important result obtained in this paper is that there is a change of Qc value before the maximum strong aftershock of Shidian 5.3 earthquake occurs. The value of Qc fluctuates uniformly within ± 1.5 times of the mean line → the value of Qc decreases gradually → Qc values appear below the variance line abnormal point → Qc values gradually returned to normal levels → seismogenic; Qidian coda Qc value is different from the more stable tectonic activity area, and the structure Jump, frequent seismic activity area, close to the low-frequency low value Qc area.