PURPOSE: A wax emulsion, prepared by emulsifying a composition containing a hydrocarbon wax having a specific melting point and a specific amount of liquid polybutadiene in water, and having improved emulsifiability, water resistance and waterproofness.

CONSTITUTION: A wax emulsion prepared by emulsifying a composition containing (A) 100pts.wt. hydrocarbon wax having 40W120°C, preferably 50W100°C, melting point, e.g. petroleum fraction wax, or synthetic or natural wax, and (B) 3W25pts.wt., preferably 5W15pts.wt., liquid polybutadiene having 500W10,000, preferably 800W5,000, number-average molecular weight in water. In emulsifying the composition, 2W20pts.wt. wax containing oxygen, e.g. oxidized paraffin or wax modified with an unsaturated polyfunctional carboxylic acid, and/or an emulsifying agent, e.g. a nonionic or anionic type surfactant is preferably incorporated. Homopolymer of butadiene or a copolymer of butadiene with a 4W5C conjugated diolefin having a low polymerization degree is used as the component (B).