Abstract: Ceramic materials to be insert-cast are disclosed, which each contain not less than 65% by volume of aluminum titanate as a crystalline phase, and have an average particle diameter of crystals thereof being not less than 10 .mu.m, Young's modulus of 50 to 2,000 kgf/mm.sup.2, compression strength of 5 to 40 kgf/mm.sup.2, and porosity of 5 to 35%. Ceramic port liners are also disclosed, which are free from cracking due to compression force during insert-casting, peeling-off during use, and facilitate insert-casting. To attain this, a reinforcement which meets either one or both of requirements that differences in coefficient of thermal expansion at 800.degree. C. and Young's modulus between the reinforcement and a material constituting the port liner body are in a range of .+-.0.1% and in a range of .+-.1,000 kgf/mm.sup.2, respectively, is filled into a depressed portion at an outer peripheral surface of the port liner body to form an integrated structure with a flat or swelled surface.