Breathable waterproof PET fabrics were prepared by the UV coating of UV-curable polyurethaneacrylate(PUA) formulation mixed with polyethyleneglycol(PEG) as a water soluble pore former. The dispersed PEG in the UV-cured coating was extracted by warm water, which can generate individual circular pores uniformly distributed all over the coating instead of pore channels. Accordingly the moisture permeability of the microporously coated fabrics increased substantially with increasing PEG addition without significant reduction of hydrostatic pressure. Also the silicone diacrylate addition in the formulation was beneficial in increasing the hydrostatic pressure. The UV-based microporous coating can be an alternative to conventional thermal curing of solventborne polyurethane coating owing to the enhanced environment friendliness and energy saving.