Abstract: Based on Cvisc model in FLAC3D，the stability coefficient of the slope in Shiyan city is sought by using strength reduction technique which considers rheological property of rock and soil medium.The creep curves of monitoring points with different reduction coefficient are obtained.Then，the displacement law of creep curves is analyzed deeply，and the long-term stability coefficient of this slope is determined.Compared with the traditional strength reduction technique，the result indicates that slope stability coefficient is 1.18 with considering rheological property，and it is 1.30 without considering.It shows that the rheological property of soil and rock makes slope more dangerous.It′s better to use stability coefficient 1.18 as design parameter of the slope support.

Key words: Cvisc model, Creep, Strength reduction technique, Long-term stability coefficient