Based on the rheological threshold theory of paste， the rheology of paste was determined by paste test with limestone powder（LP） as powder and the packing density of mortar was calculated by the basic water-powder ratio of manufactured sand mortar with different fly ash（FA） contents. Through the mixing test of manufactured sand self-compacting concrete， the effects of LP on the rheological parameters， rheological threshold and self-compacting zone were studied. The results show that with the same water-powder ratio， the yield strength and plastic viscosity of the paste mixed with LP are significantly higher than those without LP. Comparing to the self-compacting zone without LP， the self-compacting zone using the rheological threshold modified by packing density moves towards the direction of higher water-powder ratio. This reveals that the self-compacting zone is consistent with that of concrete mixed by manufactured sand if considering the effect of LP on the rheological property of paste.