Angle dispersive X-ray diffraction measurements of -Ce are performed in a diamond anvil cell under up to 0.74 GPa at room temperature. The accurate high pressure bulk modulus data obtained from ultrasonic measurements are used to calculate the parameters of various equations of states (EOSs). We find that the three order Murnaghan EOS and three order Xu EOS are fitted best to the relationships of the pressure vs. volume and the pressure vs. bulk modulus for -Ce.