中文摘要：

两四元数相似当且仅当它们有相同的实部和模,两四元数合相似当且仅当它们有相同的模.应用四维Clifford代数的矩阵表示,得到了四维Clifford代数中两元素相似或合相似的充分必要条件.

英文摘要：

It is well known that two quaternions are similar if and only if they have the same norm and real part and they are consimilar if and only if they have the same norm.Using the real matrix representations of 4-dimensional Clifford numbers,the author obtains necessary and sufficient conditions for two elements in 4-dimensional Clifford algebra to be similar or consimilar.