A carbide slotting cutter and a PCD slotting cutter were used for the slotting of the carbon-cloth CFRP, respectively. Then, the effect of the tool material on the machining quality was studied.The delamination of the slot was increased as the feed per tooth increased.It showed that utilizing the PCD slotting cutter one would achieve a stable machining quality of the slots. And an ideal machining quality of the slots will be achieved.