Modified polyurethane（PU)based hollow fiber membranes were prepared by the melt-spinning method.Influences of drawing

heat-treatment temperature and heat-treatment time on the pressure-responsive behavior were studied by the relationships between water flux and test pressure.The results showed that the hollow fiber membranes exhibited obvious pressure-responsive behavior.With increasing theoretical draw ratio

the strength of the membrane was greater and the pressure-responsive behavior was stronger.While

membrane pore size on inner surface and mean pore size became larger

the pure water flux（PWF)increased

the porosity first increased then slightly decreased.With increasing heat-treatment temperature

membrane support became worse and the pressure-responsive behavior became weaker.While

membrane pore size became smaller

the PWF and porosity of membrane increased and then decreased.With extending heat-treatment times

the deformation-recovery ratio of membrane diminished and the pressure-responsive behavior became weaker.The PWF and porosity of membrane first increased

then decreased

finally achieved stability.