本文完全确定了下述类型的有限群：（１）对于某个素数ｐ，在其Ｓｙｌｏｗｐ－子群的集合上作用双传递的所有几乎单群；（２）所有的非交换单群Ｔ，其自同构群在Ｔ的某个Ｓｙｌｏｗｐ－子群的集合上作用双传递；（３）在其所有的Ｓｙｌｏｗ子群上双传递的全部有限群．

In this paper we have completely determined:(1)all almost simple groups which act 2 transitively on one of their setsof Sylow p subgroups;(2)all non abelian simple groups T whose automorphism group acts 2 transitively on one of the sets of Sylowp subgroups of T;(3)all finite groups which are 2 transitive on all their sets of Sylow subgroups.