Fracture toughness of carbon-cloth/epoxy composites is analytically and experimentally discussed. Specimens with different angle of fiber direction are used in order to examine the anisotropy of the facture toughness K_C. The stress intensity factors of the anisotropic specimens are calculated by using the finite element method with a crack tip singular element. The effect of the specimen type, thickness, crack length and crack tip width on the fracture toughness is examines. The acoustic emisson (AE) is measured during the fracture toughness testing. The amplitude distribution and the relation between AE event count and the applied stress intensity factor are also examined.