One of the objects of the present invention is to offer novolak type phenolic resins which use phenols and aldehydes as raw materials and give narrow molecular weight distributions.The novolak type phenolic resins of the present invention are those obtained by condensation reaction of phenols with aldehydes in the presence of an oxycarboxylic acid having carboxyl groups, --COOH, and alcoholic hydroxyl groups, --OH, in one molecule. Thus obtained novolak type phenolic resins show narrow molecular weight distributions, lower viscosity in molten state and, as a consequence, uniformity in curing time.