The　effects　of　T-stress　on　the　stress　field,　creep　zone　and　constraint　effect　of　the　mode　I　crack　tip　in　power-law　creeping　solids　are　presented　based　on　finite　element　(FE)　analysis　in　the　paper.　The　characteristics　of　the　crack　tip　field　in　power-law　creep　solids　by　considering　low　negative　T-stress　and　high　positive　T-stress　are　studied　in　the　paper.　The　differences　of　T-stress　effect　on　the　crack　tip　field　between　power-law　creeping　solids　and　elastoplastic　materials　are　also　clarified.　A　modified　parameter　is　proposed　to　characterize　the　influence　of　T-stress　on　creep　zone.　The　constraint　parameter　Q　under　both　small-scale　creep　and　large-scale　creep　with　various　T-stresses　for　the　modified　boundary　layer　(MBL)　model　and　various　specimens　with　different　crack　depths　are　given.　The　applicability　and　the　limitation　of　the　MBL　model　for　creep　crack　are　also　investigated.　The　inherent　connection　between　T-stress　and　Q-parameter　is　discussed.　The　investigations　given　in　this　paper　can　further　promote　the　understanding　of　T-stress　effect　and　constraint　effect　on　the　mode　I　creep　crack.