Abstract: For a certain mine that uses cement as the backfill binder, problems such as low backfill strength and ahigh cement⁃sand ratio have resulted in high backfill operating costs. Based on the selection of backfill cementitiousmaterials and the design of mix proportion parameters for this mine, comparative strength tests were carried outbetween cemented ungraded tailings backfill using a novel cementitious material and that using cement. The basicphysical and mechanical properties of the ungraded tailings were studied, and, on this basis, the uniaxial compressivestrength of ungraded tailings backfill specimens with different cement⁃sand ratios and different slurry concentrationswas tested. The results show that the ungraded tailings from this mine are relatively fine, and the addition of surface⁃active cementitious materials can reduce interparticle friction, thereby increasing the slump. Through comparison ofmultiple cementitious materials, the novel Z9# cementitious material was found to produce a better cementing effect onthe copper mine than ordinary Portland cement of strength grade 42.5. Under the same conditions, the strength of specimensusing the novel cementitious material was 2-3 times that of specimens using cement, and the overall backfill cost of themine could be reduced by approximately 29.8 %.