In this paper, we investigate the influence of the order of nonnor-mal subgroups on the structure of finite p-groups. We use maxons(G) todenote the maximal order of nonnormal subgroups of G. This paper con-sists of four chapters. Chapter I is an introduction. Chapter II givesa list of preliminaries. In Chapter III, we classify finite p-groups withmaxons(G) = p3, where p > 2. In Chapter IV, we classify finite p-groupwith maxons(G) = pmor pm+1. |