The invention relates to an oil-in-water emulsion obtained by mixing (a) a polymer compound having, in a side chain, a group represented by formula (1): -OX).sub.n-E.sup.2-R (1) wherein X represents a C1 to C6 divalent saturated hydrocarbon group, n is a number of 5 to 300, E.sup.2 is an ether linkage or an ester linkage, and R represents a C4 to C30 hydrocarbon group, (b) a water-soluble polyol, (c) a nonionic surfactant, (d) a hydrophobic compound, and water and diluting the resulting mixture with water and a process for producing the same.