Abstract: The cemented material，P.C32.5 cement，that was previously used in the mine is replaced by a new cementing material，named cementation powder，according to the requirement of lowering costs and improving efficiency.Based on the filling ratio required in design，there was a great difference between the blocks strength in the surface laboratory test and the core strength at filling body.At the stopes of 14-1# and 10-3# at the -400 m stage，the strength of blocks at surface laboratory and underground core at different depth was extracted，and the change law of strength for two kinds of cementing materials in different curing conditions was analyzed.For cement filling stope，the underground core strength was above 1.8 MPa higher than that of blocks in the laboratory test;For glue powder filling stope，the underground core strength at the three ratio（1∶4,1∶5,1∶6）was respectively above 2.0 MPa and 1.35 MPa and 0.7 MPa higher than that of blocks in the laboratory test，and with the decrease of the ratio，the filling strength was reduced.It provides a reliable basis for further optimizing the cement-sand ratio and thereby reducing the material consumption and filling cost.

Key words: Cemented material, Filling strength, The optimization of cement-sand ratio, Filling cost