Abstract: To explore the correlation between early strength and pore structure of cemented tailing backfill sample, cemented tailing backfill (CTB) with different binders and sulphate concentrations were made and uniaxial compressive strength (UCS) tests, mercury instrusion porosimetry (MIP) tests were performed on all samples at curing time of 28 days.The relationship between early strength and pore structure of CTB were analyzed.The results show that:①in the same sealed and temperature-content condition, samples with different binders and sulphate concentrations show different UCS, void ratio and pore diameter distribution; ②there is a linear correlation between UCS and void ratio of CTB at early, which indicates that UCS shows decrease with the increase of void ratio; ③the linear correlation between UCS and void volume of pores with diameter, which is bigger than 0.2 μm is more significant than that between UCS and void ratio, were gotten.