Abstract：The whole slope can be regarded as a system，and a rule for stability limit-state equation of slope structure was established by systematically disturbing energy method according to energy principle of systemic stability. The calculation method—finite element method，is used to calculate the numerical value of disturbing energy. Due to complexity of slope structure，it is very difficult to obtain accurate formulas of slope structure limit-state function in which the independent variables are random parameters for geotechnical slope. The process and method of approximate analysis formulas，which reconstruct the disturbing energy function of the slope near the checking point by response surface method，are brought forward. Based on the dimensional definition of reliability degree，gradient decline method¾one method of optimization，was introduced to construct the grads declining calculation method of the checking point of approximate limit-state equation that was established through response surface method. There is no need to perform limit-state equation while checking point of limit state equation was solved. The gradient declining calculation method of checking point can avoid the error that was induced by linearization of limit-state equation and can improve calculation speed as well as accuracy of checking point. Finally，the steady reliability degree about an example of terrene slope and an example of rock slope，which are not be reinforced，is analyzed. Stability reliability degree of these slopes can provide important reference to reinforcing and disposal of the project. The results show that the proposed analysis method of slope stability reliability degree has a bright application prospect.
