The　mismatch　effect　in　weldments　are　widely　to　be　seen　in　engineering　practices.　In　this　paper,　the　material　mismatch　effect　on　the　mode　II　creep　crack　tip　field　is　investigated　and　discussed.　The　effects　of　material　mismatch　and　heat　affected　zone　(HAZ)　width　on　the　C(t)-integral　are　presented.　Both　the　local　mismatch　effect　and　the　general　mismatch　effect　are　found　to　play　important　roles　in　the　variations　of　C(t)-integral.　The　mismatch　effect　on　the　stress　field　of　the　mode　II　creep　crack　is　also　studied.　The　two-order　term　solutions　are　presented　to　characterize　the　material　mismatch　constraint　effect　on　the　mode　II　type　creep　crack.　Some　typical　cases　by　considering　general　mismatch　effect　and　local　mismatch　effect　are　given　so　as　to　make　comparisons　between　the　HRR　field,　FE　solutions　and　the　two-order　term　solutions.　It　can　be　seen　that　the　two-order　term　solutions　can　coincide　with　the　FE　solutions　quite　reasonably　regardless　of　creep　extent,　creep　exponent,　mismatch　factor　and　HAZ　width.　This　research　also　reveals　the　significant　effect　of　the　material　mismatch　on　the　high　order　term　solutions　under　various　conditions　for　mode　II　creep　crack.　Copyright　©　2018　ASME.