The invention provides a water dispersible polymer. The water dispersible polymer is obtained by polymerization of a hydrophobic monomer A, a macromonomer B1 and an alkenyl-containing quaternary ammonium salt monomer C; or the hydrophobic monomer A and at least one of the macromonomer B, an acrylic monomer D, a sulfonic monomer E and a phosphonic monomer F; or the hydrophobic monomer A, the macromonomer B1 and an electroneutral monomer G. The invention also provides application of the water dispersible polymer in concrete or cement. When used as a pumping agent, the water dispersible polymer provided by the invention has viscosity reduction properties, at the same time can endow concrete with good fluidity, and segregation and bleeding resistance, and ensures considerable transmission stability.