NOVELTY - An integrally woven three-dimensional preform comprises stiffeners in two directions constructed from a woven base fabric (8). The base fabric comprises first-third woven fabrics (10, 12, 14); yarns interwoven between the first and second woven fabrics; and yarns interwoven between the second and third woven fabric.    USE - For reinforced composite structures.    ADVANTAGE - The invented integrally woven three-dimensional preform provides reinforcement in more than one directions that can be woven in one process using a conventional loom without any special modifications.    DETAILED DESCRIPTION - An integrally woven three-dimensional preform comprises stiffeners in two directions constructed from a woven base fabric. The base fabric comprises a first woven fabric; second woven fabric; third woven fabric; yarns interwoven between the first and second woven fabrics, where the yarns are interwoven over a region (16) between the first and second fabrics and the first fabric is foldable relative to the second fabric; and yarns interwoven between the second and third woven fabric. The yarns are interwoven over a region between the second fabric and the third fabric, and the third fabric is foldable relative to the second fabric. An INDEPENDENT CLAIM is also included for a method of forming an integrally woven three dimensional preform comprising providing woven fabrics; interweaving yarns from a first woven fabric with yarns from a second woven fabric,; interweaving yarns from the second woven fabric with yarns from a third woven fabric; cutting the first woven fabric from a top surface of the second woven fabrics; folding together a first portion of the first fabric formed on a first side of an interwoven region of the first and second fabrics with a first portion of the first fabric formed on a second side of the interwoven region of the first and second fabrics to form a stiffener in a first direction; folding a second portion of the first fabric to form a reinforcing member for a stiffener formed in a second direction; folding a first portion of the second and the third woven fabrics to form a stiffener in a second direction; and folding a second portion of the third foldable fabric to complete a panel portion of the preform.    DESCRIPTION OF DRAWING(S) - The figure is a front view of the front of the base fabric.    Base fabric (8)    Woven fabrics (10, 12, 14)    Region (16)    Warp direction (18)    Left portion (22)