Abstract: Taking the coarse aggregate paste with gobi aggregates as the experimental slurry，the orthogonal design method was adopted to design the experimental scheme to study the influencing rules of mass concentration，cement-sand ratio，tailing-aggregate ratio and the addition of pumping agent to the compressive strength and the collapsed slump. Test results are analyzed by the range analysis and the multiple regression analysis method. The results showed that the cement-sand ratio has the greatest influence on compressive strength of the paste and these factors have the similar influence on the collapsed slump. According to the requirement of strength from the mine，the filling ratio of false bottom should be that the concentration ranges from 77 % to 78 %，the tailing/gobi aggregate ratio is from 2.5 to 3.5，the cement-sand ratio is from 0.16 to 0.17，and the addition of pumping aid is from 1.5% to 2.0%; the filling ratio of false roof should be that the concentration is from 77% to 78%，the tailing/gobi aggregate ratio is from3.0 to 4.0，the cement-sand ratio is from 0.09 to 0.11，and the addition of pumping aid is from 1.5% to 2.0%.

Key words: Unclassified tailings, Gobi aggregates, Compressive strength, Collapsed slump