Mode Ⅰ and Ⅱ delamination of continuous carbon fiber reinforced poly (phenylene ether ketone) were studied by using

respectively

double cantilever beam (DCB) specimens and end notched flexure (ENF) specimens. Mode I fracture criteria based on the linear elastic theory

GIC

and that on the elastic-plastic theory

JIC

were 0.69 and 0.63 kJ/m2

respectively. Both G/c and JIC was independent of the crack length. Stability of Mode Ⅱ delamioation depended on the ratio of crack length to half span α/L. Unstable Mode II delaminaion occured at a/L less than 0.7 and the critical energy release rate for it was 1.62kJ/m2. The critical energy release-rate for stable Mode II delamination depended on determination of the critical lwas at which crack started to grow and ranged from 1.74to 2.74kJ/m2.