To provide a manufacturing method capable of obtaining a phenolic resin binder for shell mold which has superior hardenability and thermal expansion characteristic and does not generate soot easily at deflagrating while maintaining the essentially required characteristics without containing bisphenol A which has concerns about endocrine disrupting chemicals, and to provide a resin coated sand for shell mold by using the same.

The phenolic resin binder for shell mold is obtained by making a phenolic component (A), a 1-naphthol (B) and an aldehyde (C) react with at least two or more kinds of carboxylic acids containing oxalic acid, used as the catalyser. It is desirable that a carboxylic acid other than the above oxalic acid is one or more kinds selected out of a group containing a benzoic acid, a phthalic acid, a salicylic acid, a malonic acid, a succinic acid, a fumaric acid and a maleic acid.