中文摘要：

假设H2是特征为0的代数闭域k上的Sweedler四维Hopf代数,并用r（H2）表示H2的Green环,证明了r（H2）的自同构群Aut（r（H2））同构于Klein四元群.

英文摘要：

Let H2 be the Sweedler’s 4-dimensional Hopf algebra over a fixed algebraically closed field k of characteristic 0,where r（H2）denotes the Green ring of H2.In this paper,it is shown that the automorphism group of the Green ring r（H2）is isomorphic to the Klein four group K4.