中文摘要：

根据兰州临时微震台网的数字化微震记录，采用三段几何衰减模型拟合，利用Atkinson方法和遗传算法，得到兰州市及其附近地区介质的几何衰减函数，非弹性衰减Q值随频率的关系为Q（f）=45．1f^1.488。并对研究结果对比其他地区进行了分析讨论。

英文摘要：

On the base of micro-earthquake seismogram records of Lanzhou temporary digital micro-earth- quake network, and a presumed trilinear geometrical spreading model, the inelastic attenuation Q value is investigated by using genetic algorithm and the method proposed by Atkinson. The frequency-dependent of inelastic attenuation Q value in Lanzhou City and adjacent regions is estimated as Q （f） = 45. 1f1.488. And the result is discussed and analyzed with the results from other regions.