This invention provides a method for resist under layer film formation, which can form a resist under layer film which can function as an anti-reflection film, is excellent in pattern transfer properties and etching resistance, and does not cause bending of a pattern even in the transfer of a fined pattern, and a composition for the resist under layer film for use in the method, and a method for pattern formation. The method for resist under layer film formation comprises the steps of coating a composition for resist under layer film formation (for example, a composition comprising a compound having a phenolic hydroxyl group, a solvent, and an accelerator) onto a substrate to be processed, and treating the formed coating film under an oxidizing atmosphere having an oxygen concentration of not less than 1% by volume and a temperature of 300° C. or higher to form a resist under layer film.