A water-repellent composition containing (1) a polymer having 2-100 wt %, with respect to the polymer, of a repeating unit derived from an amide group-containing monomer (a) represented by the following formula ##STR00001##
[wherein R.sup.1 is an organic moiety having an ethylenically unsaturated polymerizable group, R.sup.2 is a C.sub.7-30 hydrocarbon group, and R.sup.3 is a C.sub.1-5 hydrocarbon group], (2) a co-agent containing at least one co-agent compound selected from the group consisting of a blocked isocyanate compound, a melamine resin, a silicone polymer, a wax, an acetylene-based emulsifier, and a polyoxyalkylene group-containing emulsifier, and (3) a liquid media. Preferably, the water-repellent composition includes no fluoroalkyl group-containing monomer, and preferably no fluorine-containing monomer. Also disclosed is a method for producing the water-repellent composition, a method for treating a substrate with the water-repellent composition, and a method for producing a treated textile product which includes treating a textile product with the water-repellent composition.