Based on analyzing the existing literature about the research on coupling of the seepage and unloading stress of the fractured rock and by means of collection, analysis of data in field and simulation test in laboratory, a coupling model of seepage and unloading stress is set up, which is verified and tested by the field data and simulation test.

However,researches on the rheological property under unloading stress path are seldom taken into account.

Comparison between the results obtained from the improved model and tests shows that the proposed rheological model can describe the overall rheological deformation law of rock with time under unloading stress path.

For the sake of recognizing the characters of excavation engineering rock mass in nature, the authors, who, based on the unloading rock mass mechanics, discuss the deformation and destruction characters, the methods of stability analysis and the design theories of the slope engineering rock mass.