Abstract: Experiments were conducted to test the uniaxial compressive strength and longitudinal wave velocities of tailing cemented backfills which are made of 42.5 (R)and 52.5 (R)normal silicate cement separately. Testing Results show that backfill with 52.5 (R)cement is more stable than that with 42.5 (R) cement. Cement 52.5(R), instead of cement 42.5 (R), can reduce the backfill proportion by decreasing the cement usage in the mining industry.