Based on the endochronic theory, the basic principle ofthe irreversible thermodynamics of continuum media was used to derive a newendochronic rheological constitutive equation of frozen soil by redefiningthe intrinsic times. The corresponding parameters in the endochronicequations can be determined by the method of the Matlab fitting. Thesolution, analysis and experimental validation of the new equations underuniaxial and triaxial stress were performed. The stress-strain curves oftheoretical calculation are very consistent with the experimental results.Therefore endochronic theory, compared with plastic theory, can be used toavoid the determination of yield surface. Finally, by utilizing theconstitutive relation, we discuss and analyze the numerical solutions offrozen roadbed. The results indicate that the endochronic theory has itsextensive applicability.