4-Valent Cayley Graphs Of Order 2pq

Let G be a finite group and S a subset of G such that 1（?）S. A Cayley graph X=Cay（G,s）of group G is said to be normal if R（G）,the group of right multiplications is normal in Aut（X）.Denote G=(a,b|a^pq=b²=1,ab=a^1-p),where p,q are odd primes, p>q>5,and q | p-2.In this paper,by investigating the normality of G,we classify its 4-valent Cayley graphs,and prove that any 4-valent Cayley graph.X=Cay（G,S） is normal.