Abstract: ontophoresis of pulse current with various current intensity ,frequency , on/off ratio and duration of treatment was used to facilitate the transdermal delivery of insulin in order to control blood glucose levels in diabetic rats. Male Spraque-Dawley rats were made diabetic by ip injection of streptozotocin (65 mg·kg^-1 body weight).After two days, diabetic rats were anaesthe-tized with urethane (as 25%aqueous solution,1.5 mg·g^-1).Both thereservoir electrodes and thereceptor electrodes were applied on the abdominal site of the diabetic rats.Iontophoresis was carriedout using a prototype transdermal periodic iontophoretic system in order to provide the required directcurrent with desired pulse modes.The extent of reduction of blood gl ucose levels was found to bepositively correlated with the current intensity ,frequency and duration of treatment to some extent。But when the current intensity was over 0. 8 mA/cm² and the frequency was over 3000 Hz,thereduction of blood glucose levels did not continuously increase, Blood glucose levels were found to be better controlled when the on/off ratio of l :l was used.