The shock wave propagation characteristics of the polyester have been measured by recording the shock wave profile produced by the impact of projectiles accelerated in a light gas gun. The impact velocities in the experiments were from 323 m/s to 526 m/s, and the corresponding peaks of impact stresses in the targets were from 0.632 to 2.137 GPa. The Hugoniot relation, expressed as the curve of shock wave velocity versus particle velocity, obtained from the experiments shows linearity in the testing stress range. The polynomial equation of state is obtained by regression of the experimental data and the Grüneisen coefficient is calculated.