To　take　into　account　of　the　coupling　effects　of　different　fracture　modes　for　composites　interface　crack　under　mixed　mode　loading　conditions,　a　novel　fracture　onset　and　growth　criterion　was　proposed　based　on　mode-mixing.　In　addition,　the　application　of　the　criterion　for　predicting　delaminaiton　in　modern　aeronautical　composite　skin/stringer　structures　was　also　studied.　The　good　correlation　of　the　results　demonstrated　the　effectiveness　of　the　proposed　criterion.