To provide a composite that can find application to various uses in a wide spectrum of fields, for example, sealing members, such as a joint sheet, a gasket and a packing, for use in junction portions, etc. of pipings of power plant and chemical plant, radiation sheets, electromagnetic wave shielding members, soundproof sheets, etc., and provide a process for producing the composite; a gasket or packing based on the composite and a clay dispersion liquid used for the composite. There is provided a composite composed mainly of graphite and clay and having the structure of graphite laminated with and/or impregnated with clay. The composite is produced by subjecting an exfoliated graphite sheet or film or a molding therefrom to coating with and/or immersion in a clay dispersion liquid with clay particles dispersed therein, or by laminating together of an exfoliated graphite sheet and/or film and a sheet and/or film composed mainly of clay. Further, a gasket or packing is produced by molding the composite.