The compression test was conducted on the homemade and T300 carbon fiber composite laminate with one delamination. According to the macro-shape and the ultrasonic C-scan result of post-failure specimens which contain different sizes and different positions of delaminations but the same thickness

an investigation has been conducted by this study on the effects of delmaination sizes and positions on the failure mechanism of homemade and T300 carbon fiber composite laminates. Also the differences of failure mode have been analyzed between these two kinds of composites. The final result shows that the imbedded delaminations have all propagated

and the position of delamination proposed to be the most important factors affecting the compressive failure mode. To the laminates with deep delamination the failure mode presented to be the first propagation of delamination and second shear buckling failure of sub-laminate. Based on these analyses we find that the failure mode of homemade carbon fiber composite is same with the T300 carbon fiber composite generally.