In this paper, an investigation was performed on the Mode II dynamic interlaminar fracture toughness of unidirectional CFRP laminates. The stacking sequences used in this experiment are two kinds of [0˙_(20)] and [0˙_(10)/F₂/0˙_(10)]. In the experiments, Split Hopkinson`s Bar test was applied to dynamic and notched flexure test. The Mode Ⅱ fracture toughness of each unidirectional CFRP was estimated by the analyzed deflection of the specimen and J-Integral with the measured impulsive load and reactions at the supported points. As an experimental results, the specimen [0˙_(10)/F₂/0˙_(10)] appears greater than that of [0˙_(20)] for the J＾-integral and displacement velocity at a measuring point within the range of experiment.