To obtain a reinforcing fibrous material woven fabric for molding a fiber-reinforced plastic capable of readily discriminating a weaving slippage without deteriorating mechanical characteristics of a matrix resin by arranging tracer fibers having a specific value or below of percentage of moisture absorption in the weft direction and/or the warp direction of the reinforcing fiber woven fabric.

This reinforcing fiber material woven fabric for molding a fiber-reinforced plastic is obtained by arranging reinforcing fibers 1, preferably carbon fiber filaments in the wrap yarn and the weft yarn directions and arranging tracer yarns 2 comprising low water absorbing poly-p- phenylenebenzobisoxazole fibers having ≤2.5% percentage of water absorption in the weft yarn direction at 50-2.5 cm interval and/or 25-2.5 cm interval in the warp direction and carrying out the weaving.