Alumina paper containing alumina short fibres as a main constituent was developed for use as a new reinforcing material of composite materials. The alumina short fibres, the constituent of the alumina paper, have high electric insulating properties, thermal conductivity, thermal resistance, abrasion resistance, and so forth. These properties were expected to contribute to the high performance of composite materials. The alumina paper is prepared by distributing the alumina short fibres in water uniformly, and papermaking by use of a small amount an organic binder. This paper describes the research results on papermaking technique for producing alumina paper, the characteristics of the alumina paper, and the exemplified application for printed circuit boards. The alumina paper was shown to have satisfactory properties.