The　circumferential　welding　joints　of　strain-based　design　X70　pipeline　always　fractured　at　heat　affected　zone　in　the　tensile　test.　The　crack　driving　force　and　fracture　resistance　curve　of　the　circumferential　welding　joint　defects　were　obtained　by　numerical　simulation　and　impact　toughness　test　separately.　On　the　above　basis,　the　considerable　high　strain　capacity　has　been　demonstrated　by　the　tangent　method　and　verified　by　wide　plate　tensile　test.　The　results　proved　that　the　pipeline　had　considerable　fracture　resistance　which　may　lead　to　high　strain　capacity　and　the　crack　driving　force　approach　was　more　reasonable　than　current　standard　which　required　that　the　weld　joint　should　not　be　fractured　in　the　vicinity　of　the　weld　zone,　and　remitted　the　over-demand　from　material　properties.　©　2018,　Editorial　Board　of　Transactions　of　the　China　Welding　Institution,　Magazine　Agency　Welding.　All　right　reserved.