This paper focuses on the analysis of the mechanical behaviour of alumina/alumina ceramic matrix composites (CMCs) developed by a continuous tow impregnation method, in relation to their microstructures. The influence of the aqueous slurry formulation on the microstructures of the materials and their tensile and bending properties is studied. A combination of a hygroscopic plasticizer (glycerol) and a gelling powder (boehmite) within the slurry is needed to obtain a good interply cohesion in the composite. A large amount of glycerol (20 wt.% relative to the alumina mass) allows a fine-scale porosity distributed throughout the matrix with few large pores which allows to reach a high Young’s, around 130 – 150 GPa. Moreover, reducing the plasticizer amount induces the apparition of delaminations and defects appear the microstructure, hence decreasing the stiffness. Then, increasing the boehmite amount (from 5 wt.% to 10 wt.%), the damage tolerance is enhanced, likely due to a higher densification level induced by the presence of the boehmite powder.