Abstract: In order to study the phenomena and regularities of static settlement process of tailings backfill slurry, a kind of aggregate with specific particle size distribution (DSP) has been prepared by using a mine’s underflow coarse tailings and overflow fine tailings. And sires of static settlement experiments of tailings slurries with different water binder ratios and concentrations have been done by using the aggregates. By observing the phenomena and analyzing the results of experiments, the conclusion that the final settlement concentration of slurry is positively correlated with the initial concentration has been made. And it has also been found that porosities, moisture contents and particle size differences of consolidated tailing bodies are all factors that will affect the strength uniformity of backfill bodies. The mechanism of segregation of aggregates caused by static settlement processes has been found at the mean time. Namely, the segregation of coarse and fine aggregates is mainly determined by the hindered settlement processed of particles and the movements of fine aggregates caused by seepage force of bleeding water.