Electrotopological state（E-state） indices were used to describe the molecular structures of 136 polychloridized phenoxazine（PCPX） compounds

while five quantitative structure-property relationship（QSPR） models（r2>0.995） were got by multiple linear regression method.These models based on E-state indices were created to predict thermodynamic properties of 136 PCPXs

including thermal energy（Eth）

heat capacity at constant volume（CV）

standard entropy（S）

standard enthalpy（H） and free energy（G）.In order to test the stability and predicted ability of the model to S

the Jackknifed cross validation was performed.The good results（r2 >0.999）were obtained

and the relative mean deviation between the literal and predicted values of S was 0.14%.The result showed that the QSPR models possessed good stability

correlation degree and predictive ability.