Abstract: Physics and mechanics performance of paste-like backfill material in coal mine such as strength, allowable specific pressure and compressive rate was researched by experiment.The results show that after curing for 12 hours the backfill material can achieve sufficient strength to keep stable with the content 3% of sialite and the slurry density above 78%; After curing for 28 days the backfill material can achieve sufficient allowable specific pressure to avoid insertion of prop into floor with the content 3% of sialite and the slurry density 80%; Paste-like backfill material has far smaller compressive rate than sand,fly ash gangue powed and so on.