In this research, the capability of utilizing fluidic flexible matrix composites (F 2MC) for autonomous structural tailoring is investigated. By taking advantages of the high anisotropy of flexible matrix composite (FMC) tubes and the high bulk modulus of the pressurizing fluid, significant changes in the effective modulus of elasticity can be achieved by controlling the inlet valve to the fluid filled F 2MC structure. The variable modulus F 2MC structure has the flexibility to easily deform when desired (open valve), possesses the high modulus required during loading conditions when deformation is not desired (closed valve - locked state), and has the adaptability to vary the modulus between the flexible/stiff states through control of the valve. In the current study, a closed-form, 3-dimensional, analytical model is developed to model the behavior of a single F 2MC tube structure. Experiments are conducted to validate the proposed model. The test results show good agreement with the model predictions. A closed/open modulus ratio as high as 56 times is achieved experimentally thus far. With the validated model, an F 2MC design space study is performed. It is found by tailoring the properties of the FMC tube and inner liner, a wide range of modulus and modulus ratios can be attained.