PURPOSE: To inexpensively and efficiently obtain the subject raw paper having excellent mechanical strength, etc., without disposing a process for impregnating a resin by dispersing specific resin fine particles in a pulp suspension and subsequently subjecting the dispersion to a wet paper-making process.

CONSTITUTION: Mother particles comprising the fine powder of a water-soluble thermosetting resin (e.g. a phenolic resin) are mixed with child particles comprising the fine powder of a hydrophobic thermoplastic resin (e.g. styrenic resin), and a compression force and an abrasion force are applied to the prepared mixture to prepare resin fine particles where the child particles are stuck to the surfaces of the mother particles. The resin fine particles are dispersed in a pulp suspension and subsequently formed into the objective raw paper by a wet paper-making method. A stirrer such as Henschel mixer is preferably employed for applying the compression force and the abrasion force to the mother and child particles.