By combining the advantages of PTNS and PNM and incorporating the technique of deep insertion of long acupuncture needles, the investigators developed electrical pudendal nerve stimulation (EPNS). In EPNS, long acupuncture needles of 0.40 Х 100 or 125 mm were deeply inserted into four sacral points and electrified to stimulate the pudendal nerves (PN). CT transverse plane at the coccygeal apex has showed that the position of the lower needle tip is similar to where (adjacent to PN at Alcock's canal) the Bion device is implanted for chronic PN stimulation. Besides the radiographic evidence, simultaneous records of perineal ultrasonographic pelvic floor muscle contraction, vaginal pressure and pelvic floor surface electromyogram in our previous study have proved that EPNS can exactly excite PN. The purpose of this study is to compare the efficacies of EPNS versus TES in treating female UUI.