Abstract: The slurry-ability of municipal sludge conditioned by semi-coke and the mixtures from conditioned sludge and coal were investigated using slurry performance experiment. The results indicate that the ratio of semi-coke could be viewed as a key factor for the slurry-ability of conditioned sludge. And the slurry-ability of conditioned sludge was improved with the increase of semi-coke ratio. When the ratio of semi-coke was greater than 80% ,the slurry concentra- tion of conditioned sludge was still merely 33. 88% ,which suggests the quality of the slurry is not satisfactory. The weight fraction of conditioned sludge had a significant impact on the slurry-ability of blended conditioned sludge / coal feedstock. The correlation between the weight fraction of conditioned sludge ( x) and slurry concentration ( φ) could be quantitatively described by the linear function as follows:φ = 68. 835 1-1. 201 1x, R2 = 0. 953 6. The increase in the weight fraction of conditioned sludge would undermine the slurry-ability of the conditioned sludge / coal feedstock. The coal-sludge water slurry exhibited a pseudo-plastic behavior with shear thinning property. The research results a- bove are important for preparing sludge coal slurry with a high energy efficiency and converting sludge into a source of energy.