Abstract:The sticthing technique as the monolithic molding and lowcost manufacture technique has been widely applied in aeronautics. The stitch threads used in stitching process are needed to be twisted in order to improve the characteristic of service. The degree of the twist affects the sticth threads and the sticthed composites. The Kevlar stitch threads used popularly are studied here.The permeability and breaking strength of Kevlar stitch threads with diffetent degrees of twist are investigated experimentally, whilst the effect of Kevlar stitch threads are discussed with diffetent degrees of twist on the tensile property,bending property and interlaminar shear property of sticthed composites by chained stitching and lockingtype stitching. The Kevlar stitch threads with the best degree of the twist are confirmed by the experimental results.