The stress-strain relations and fracture behavior of the PEG/N-100 matrix were investigated by methods of unilateral tensile testing, scanning electron microscopy, etc.. The experimental results indicate that maximum tensile strength of the PEG/N-100 matrix is above 7 MPa and approximately 10 MPa at the yield point, and the elongation percentage of fracture is over 400%. The spherulites of about 7 μm in diameter were found in the fractured matrix of PEG/N-100. The process of the matrix fracture has been proved to undergo the growth of micro-cracks, the expansion of micro-cracks and the final fracture of PEG/N-100 matrix.