In this work, super-critical cohesion parameters for Soave-Redlich-Kwong (SRK) equation of state (EOS) were adjusted by fitting cohesion parameters to the reliable Joule Thomson Inversion Curve (JTIC) data. For this purpose, the reliable JTIC data for CH4 and CO2 were adopted from literature. To evaluate the result, the modified SRK EOS was also compared to the EOSs including square-well (SW) EOS, four-parameter Trebble-Bishnoi (TB) EOS and Peng-Robinson (PR) EOS. Moreover, The JTICs obtained from the new EOS for nine substances Ar, Ne, N-2, O-2, C2H4, C2H6, CO2, CH4 and CO indicated new EOS abilities to present good predictions, while the SRK EOS produced the results underpredicted at high-temperature regions. In addition, a detailed analysis of the ideal curves including JTIC, Boyle curve and Zeno line and also compressibility factor curve, which were calculated by the new EOS was carried out. (C) 2011 Elsevier B.V. All rights reserved.