Energetic poly(glycidyl azide) (PGA) elastomers with different crosslink densities were prepared by varying the NCO/OH reactive-groups ratio from 0.8 to 1.0. In the preparation of the elastomers, PGA chains were end-liked with a mixture of hexamethylene diisocyanate (HMDI) and trimethylol propane (TMP) at a fixed TMP/PGA mole ratio. The number average molar mass between junction points of the network chains <(M)over bar (c)> was calculated using data obtained from swelling and uniaxial tensile tests and the results ware compared. For the mechanical characterization of the networks, Mooney-Rivlin plots were prepared and the values of the constants 2C(1) and 2C(2) of PGA networks having different crosslink densities were determined.