A series of soft segment crystallinity waterborne polyurethane (WPU) were prepared through a prepolymer process using dimethylol propionic acid (DMPA) as hydrophilic group. The properties of WPU dispersions and films were characterized by FT-IR, particle size analyzer, contact angle measuring instrument, and X-ray diffraction (XRD). The results of experiment showed that with DMPA content increase, the particle size of WPU decreases, zeta potential and dispersion viscosity increases; the contact angle and elongation at break of coating decrease with increase of DMPA content; the tensile strength increases with increase of DMPA content; the crystallinity of soft segment decreases with the increase of DMPA content; the amorphous state presentes in the soft regions when the w-DMPA was above 5.6%.