Abstract: In order to study the deformation law of backfill under high stress and lateral restraint，according to the site survey results，nine-load creep experiments on the backfill with the gray-sand ratio of 1∶10 and a concentration of 70% are carried out.Axial deformation law of backfill is obtained under each level of load stress.Compression characteristic analysis of backfill is made to get the variation of compression factor and compression modulus under different loading stresses.Through the compression strain-time diagram，the compression deformation mechanism of backfill under high stress and lateral restraint is drawn.The results provide a scientific basis for the filling design and production safety in Xincheng Gold Mine.

Key words: Backfill, Lateral restraint, Compression characteristic, Deformation mechanism