Abstract: An ion-selective electrode for bismuth(Ⅲ) prepared from carbon paste electrode with the ion-association complex of BiI3-6 with norfloxacin as electroactive substance was reported.Nernst response of this electrode for Bi(Ⅲ) was found in the range from 1.0×10-2 to 4.0×10-6mol·L-1 with a slope of 20 mV/pc.The detection limit reported was 2.5×10-6mol·L-1.The time of response was less than 90 s.This Bi(Ⅲ)-ISE has been used in the determination of bismuth in bismuth potassium citrate capsules using the standard curve method.The results obtained by this method checked very well with those obtained by pharmacopeia method.