若有限群G的每个极小子群及4阶循环子群在G中正规,则称G为PN^*-群.本文给出了有限群的每个真子群都是PN^*-群但其本身不是PN^*-群的完全分类.
A finite group G is called a PN*-group if all minimal subgroups and all cyclic subgroups with order 4 of G are normal in G. In this paper, we give a complete classification of those finite groups which are not PN*-groups but whose proper subgroups are all PN*-groups.