Abstract: The mixture amount and particle size distribution of tailings in cement admixture have a certain influence on the cement property.In order to increase the property of cement admixture with tailings，the effect of particle size distribution of lead-zinc tailings on fluidity and compressive strength of its cement mortar was studied by using a lead-zinc tailing from Youxi county Fujianas province as main admixture through grey connection analysis.The result showed that the mortar′s fluidity and compressive strength can be increased by increasing grinding fineness of the tailings.With the tailings dosage of 30%，both mortar fluidity and compressive strength have a negative correlation with particle size of tailings +8.39 μm，and a positive correlation with particle size of tailings -8.39 μm.Among these，the maximum correlation with particle size of 4.24~8.39 μm，followed by 4.24~2.15 μm，2.15~1.09 μm，1.09~0 μm.To improve the property of cement admixture with lead-zinc tailings，and with the dosage up to 30%，proportion of particles -8.39 μm should be increased，especially the portion of 4.24~8.39 μm，and the portion of particles +8.39 μm should be decreased.

Key words: Lead-zinc tailings, Particle size distribution, Fluidity, Compressive strength, Grey connection analysis