Abstract: The unclassified tailings as aggregate and the cement as gelling agent were used in Hui Bao Ling Iron Mine for subsequent filling,and proportion test on backfilling material of cemented unclassified tailings was carried out to study the slurry fluidity and strength of filling body.Based on regression orthogonal combination design,slurry slump degree of unclassified tailings,strength properties of filling body within 28days and 90days were researched.Results showed that the slurry′s pump ability was great with slurry concentration varying from 70percent to 75percent.And the compressive strength,elastic modulus,cohesion of filling body cured for 28days and 90days have an increase tendency with the augment of slurry concentration in weight and cement dosage.It is revealed that the best strength performance of filling body,with concentration 75percent and cement dosage 10.5percent can be achieved by strength properties regression analysis,which meets the production of the mine.