2-Hydroxyethyl methacrylate (HEMA) modified polyurethane dispersions (PUD) was prepared from the poly(tetramethylene ether) glycol(PTMG), toluene 2,4-diisocyanate (TDI), dimethyol propionic acid (DMPA), and 2-hydroxylethyl methacrylate (HEMA), as a modifier, Differential scanning calorimeter (DSC), FT-IR, GPC, universal testing machine (UTM), and particle analyzer were utilized to characterize the physical and mechanical properties of PUD according to HEMA contents. As the content of HEMA in PUD increased, the particle size increased, before and after crosslinking, but the particle size were not evenly distributed. PUD was synthesized by increasing [NCO]/[OH] mole ratio to 1.4, 1.8, 2.2, while varying the content of HEMA to be 0~10% of the standard of polyol mole; the molecular weight of PUD was reduced as [NCO]/[OH] mole ratio increased, but it was not greatly affected by the change of HEMA content. The molecular weight of PUD, however, was increased by the effect of crosslinking, which was caused by HEMA. Increasing HEMA content, also increased tensile strength but the elongation at break decreased. Glass transition temperature (Tg), however, did not change significantly by change in the content of HEMA.