In　this　paper,　dual　boundary　element　method　(DBEM)　is　combined　with　interaction　integral　(I-integral)　to　evaluate　stress　intensity　factors　(SIFs)　and　T-stress　simultaneously　for　mixed-mode　crack　analyzing.　DBEM　is　proved　to　be　one　of　the　most　efficient　boundary　element　methods　(BEM)　for　solving　crack　problems　with　boundary-only　discretization,　however　its　current　implementation　is　in　lack　of　efficient　methods　to　evaluate　fracture　parameters.　The　available　geometrical　extrapolation　method　and　J-integral　technique　for　calculating　fracture　parameters　in　combination　with　DBEM　are　imprecise　and　difficult　to　be　implemented　in　mix-mode　crack　analysis.　The　presented　combined　DBEM　and　I-integral　approach　can　be　easily　used　to　extract　SIFs　and　T-stress　for　mixed-mode　cracks,　which　does　not　need　the　decomposition　of　elastic　field　into　symmetric　and　antisymmetric　components.　The　fundamental　basis　lies　in　the　introduction　of　auxiliary　fields　for　some　proper　defined　single　mode　crack,　then　fracture　parameters　are　calculated　by　evaluating　the　formulated　I-integral　in　terms　of　DBEM　solution　and　auxiliary　elastic　fields.　In　this　paper,　the　basis　of　DBEM　is　illustrated　at　first,　then　the　explicit　expressions　for　auxiliary　fields　of　displacement　gradients　are　derived,　then　an　automatic　scheme　for　generating　the　path　of　I-integral　is　presented.　Several　numerical　examples　are　given　to　validate　correctness　of　the　presented　method.　©　2020　Elsevier　Ltd