本文通过菲涅耳-基尔霍夫衍射积分方法，推导了一般稳定和非稳定球面镜谐振腔中自再现模的解析表达式，揭示了从稳定腔变为非稳腔过程中自再现模的变化规律. 进一步地，本文在几何光学近似条件下得到了非稳腔的自再现模，通过与衍射积分结果对比，发现基于几何光学近似得到的非稳腔最低阶偶对称模（即基模）和最低阶奇对称模的空间分布与衍射积分结果一致. 而对于更高阶的自再现模，当非稳腔接近稳定腔时，几何光学近似得到的自再现模空间分布和衍射积分结果之间存在较大差异. 本文的结果可以作为激光原理教学内容的重要补充.

In this paper, the analytical expressions of selfreproducing modes in general stable and unstable spherical mirror resonators are derived by Fresnel-Kirchhoff diffraction integral method. The law of self-reproducing modes changing from stable resonator to unstable resonator is revealed. Furthermore, the self-reproducing mode in the unstable resonator is also obtained under the condition of geometric optics approximation. By comparing with the diffraction integral results, it is found that the spatial distributions of the lowest-order even symmetric mode (i.e., fundamental mode) and the lowest-order odd symmetric mode of the unstable resonator obtained based on geometric optics approximation are consistent with the diffraction integral results. For higher-order self-reproducing modes, when the unstable resonator is close to the stable resonator, there is a large difference between the results from the geometric optics approximation and the diffraction integral. The results in this paper can be used as an important supplement to the teaching content of laser principle.