In this paper, a new multi-direction three-dimensional fabric, called in-plane quasi-isotropic fabric, including warps 0, wefts 90o, a set of bias yarns ±45o, and a vertical yarns Z fastening the other yarns together is designed. Unit cell models are established on the basis of the rule of yarn movement and on the basis of optimizing the yarn cross section on the method of braiding-solidify-cutting-polishing-viewing. Mathematical relationship of the parameters with geometry parameters is founded and the fiber volume content is calculated, the valid relationship is proved by experimental results.
