Time integrated soft X-ray spectra were obtained from a carbon plasma irradiated by a high power iodine laser using a flat-field XUV spectrograph. The radiation intensity of an iodine laser was 3 × $10^{11}$ W/㎠. The electron temperature was calculated from the intensity ratio of He-β ($1s^2$-1s3p) to He-α ($1s^2$-1s2P), and of Ly-β (1s-3p) to He-α (1s-2p) based on the Local Thermodynamic Equilibrium (LTE) model and the non-LTE (Collisonal Radiative Equilibrium, CRE) model. The non-LTE code, RATION was used to calculate the intensity ratio. These methods gave the electron temperature of 26-45 eV. The electron temperature of 29-59 eV was also estimated by C V continuum spectrum. The electron density was calculated by Ingris-Teller method for the C VI Lyman series. It gave the electron density less than 7 × $10^{20}$/㎤. The temperature and the density showed that the plasma state is slightly deviated from the LTE condition. The laser plasma simulation code, MED:101 was used to confirm the experimental result.
