文献〔1〕给出了震源在地表时计算理论地震图的部分分离变量——有限差分方法。本文继〔1〕讨论了震源在介质内部时,特别是震源在介质分界面上时理论地震图的计算方法。含贝塞尔函数的数值积分是用FiLon方法完成的,它具有精度高,运算速度快的特点。作为例子,本文最后给出了利用所述计算方法得到的不同内源在含两个高速夹层地壳模型中的理论地震图。 Reference [1] gives a partial separation variable-finite difference method for calculating the theoretical seismogram when the source is at the surface. This paper follows [1] to discuss the calculation method of theoretical seismogram when the source is in the medium, especially when the source is at the medium interface. The numerical integration with Bessel function is done by FiLon method, which has the characteristics of high precision and high computing speed. By way of example, the theoretical seismograms from different endogenous models with two high-velocity intercalated crusts obtained using the above calculation method are given.