| It is important to study the structures of finite groups by combining some subgroups with some properties in the researches on finite groups. In this paper, we discuss the following:(1) The relations between the θ-pairs of maximal subgroups and c-normality , weak c- normality , s-normality , the normal index of maximal subgroups;(2) Some results on solvablity of finite groups that are obtained by using the s-normality of subgroups;(3) The θ-pairs of general proper subgroups of finite groups as the generalization of the θ-pairs of maximal subgroups that is used to describe c-normal subgroups , weak c- normal subgroups and s-normal subgroups, by which some new results on finite groups are obtained;(4) Some new results on p-quasinilpotent groups and p*-nilpotent groups. |