Abstract: In order to study the mechanism of freeze-thaw damage and failure of granite with fissures， four groups of granite samples with prefabricated fissures inclination angles of 0°，15°，30° and 45° are sub‐ jected to freeze-thaw cycle tests. The strain gauge and thin film sensor are used to measure the frost heaving force and the strain change at the crack tip during the freeze-thaw process，and the frost heaving force，longi‐ tudinal and transverse strain of the rock samples with freeze-thaw cracks are analyzed. The results show that with the increase of freeze-thaw cycles，the longitudinal and transverse strains of fractured rock mass in‐ crease gradually，while the frost heaving force decreases gradually. The larger the inclination angle of the initial prefabricated fissure，the smaller the variation range of the longitudinal and transverse strains of the frozen-thawed rock sample. According to the variation trend of longitudinal and transverse strains and frost heaving force of granite under single freeze-thaw cycle，it can be divided into six stages of inoculation，frost heaving damage，recrystallization，thermal expansion stage，melting reduction and residual deformation. The more the number of freeze-thaw cycles，the more serious the internal damage of the rock sample，resulting in the greater residual strain of the freeze-thaw fissured granite rock.

Key words: freeze-thaw cycle, fissured rock, frost heaving force, strain