Provided are a latex for dip molding, a composition for dip molding, a preparation method of a dip molded product, and a dip molded product prepared thereby. The latex for dip molding includes a conjugated diene monomer, an ethylenically unsaturated nitrile monomer, and an ethylenically unsaturated acid monomer, wherein the latex further includes sodium methallyl sulfonate as a copolymerizable ionic monomer. A dip molded product having excellent tensile strength, elongation, and touch may be obtained from a composition using the latex according to the present invention, and the generation of limitations, such as non-uniformity of physical properties and difficulties in product management, may be prevented.