A novel 3D fabric structure is defined and modeled. The 3D hybrid woven/knitted fabric has a structured that can be categorized in the same group of 3D multiaxial warp knitted structures. The fabric consists of longitudinal yarns in the X direction and two bias yams, which are employed to bind the multilayers of warp yarns on the Z axis with an angle of +/-45degrees without any need for weft yarns. The model of the structure is defined by basic geometric relations using fundamental yarn and fabric characteristics. The geometric model is compared with the experimental results, and the length of each 3D loop, the length of the needle loop, the bias yarn consumption per unit length of the fabric on a single warp yarn, and fabric thickness are verified. Monofilament and multifilament yarns are used for sample production. There is reasonable agreement between theory and experiment, considering the assumptions made and the complexity of the 3D fabric structure. The deviation between the model and experiments is less with monotilament warp yams.