An aqueous polyolefin resin dispersion, a process for producing the same,
and a water-based coating material comprising the same are provided. The
aqueous polyolefin resin dispersion contains a polyolefin resin
containing 50 to 98% by mass of an unsaturated hydrocarbon having 3 to 6
carbon atoms and 0.5 to 20% by mass of an unsaturated carboxylic acid
unit, and a basic compound, and contains substantially no
water-compatibilizing agent having a boiling point of 185.degree. C. or
higher at normal pressure. The polyolefin resin has a number average
particle size of 1 .mu.m or smaller in the aqueous dispersion.