prostate urethra stent of NiTi memory alloy has fine biocompatibility and corrosion resistance, and it also has special property of memory and superelasticity. Under 0～10℃ (ice water), the stent is soft and its shape can be changed to a certain extent. Deliver it to the narrow area of the body by delivery device and the stent would immediately restore to its original shape after being released under body temperature. It would generate soft and lasting radial expansion to the wall of the urethra, restoring the narrow parts to normal state. It closed attached to the inner wall of urethra, inlaying the mucosa, promoting epithelia cells to cover and avoiding formation of stones.