An actinic ray-sensitive or radiation-sensitive resin composition includes (A) a resin having at least two of repeating units represented by general formula (1) below and exhibiting increased solubility in an alkali developer when acted on by an acid, and (B) a compound that generates an acid when exposed to actinic rays or radiation. ##STR00001## In the formula, each of R, A, R.sub.0, Z, L and n represents the same as defined in the claims and in the specification.