Abstract: In order to satisfy the data demands and requests for composite structure-s producibility of manufacture process in the composite structures- digital development environment, the whole contents of digital definition of aircraft composite structures for manufacture were summarized. The direction datum for composite structures digital models was constructed by defining direction coordinate systems. According to the difference of composite structures- Gaussian curvature, the direction coordinate systems were divided into three kinds. The definition methods and mapping rules of these three kinds of direction coordinate system were presented. The contents and classification of geometric data, relationship of composite objects to geometric data and the hierarchy of composite objects in the definition data of laminate lay-up in 3D model were studied. The detail contents and definition methods of process information were summarized, and constructing views based on the above-mentioned data classification methods were used to organize and manage the datasets of digital definition.