Provided are a thickener by an inverse emulsion polymerization method and a production method thereof for the substitution of an alkaline swelling thickener or a cellulose-based thickener used to control flowability and physical properties of a common industrial product. The production method includes (a) preparing an aqueous phase having an unsaturated double bond; (b) preparing an organic solvent phase used as a dispersing medium; (c) preparing an emulsion of an initial emulsion state by adding the aqueous phase prepared in step (a) to the organic solvent phase prepared in step (b) and stirring the mixture at high speed; (d) performing a polymerization process by adding an initiator to the emulsion prepared in step (c) and increasing the temperature; and (e) aging for minimizing the remaining amount of unreacted monomers during the polymerization process in step (d) and for improving the stability. The viscosity, the flowability, and the workability during industrial mixing may be controlled.