Abstract: Paste filling techniques are increasingly being used in underground mining，and rheological properties of the paste is the basic characteristic parameters to ensure its smooth delivery and filling.Analysis of the rheological properties of traditional paste mainly relies on indoor rheometer，and there will be sizeable deviations between the test results and the actual site.Therefore，in order to obtain real rheological properties of paste filling slurry in transportation process，this paper analyzed stress state during paste pipeline flow based on hydrodynamic theory，designed incline pipeline experimental device.Studied the paste mass fraction，gray sand ratio，the amount of fine tailings added，the amount of coarse particles added four kinds of factors affect on rheological properties of a mineral paste with the help of uniform design experimental methods.A function of various factors on the slurry yield stress and plastic viscosity was obtained.The results showed that:for Bingham fluid under laminar flow conditions，use incline plumbing device can be easily and quickly measure the relevant rheological parameters；slurry mass fraction play a decisive role on rheological parameters，and the impact of gray sand ratio can be ignored，when the fine tailings content 12%，gravel content 4%，the paste has a low yield stress and plastic viscosity，good fluidity.

Key words: Paste backfill, Rheological properties, Inclined pipeline, Yield stress, Uniform Design