In order to preparing strontium ion selective electrode 6-(4- nitropheny1)-2-pheny14, 4- dipropy1-3, 5-diaza-bicyclo [3, 1, 0] hex-2-ene (NPDBH) was used as an ionophore. This electrode responds to Sr (II)ion with a sensitivity of 28.2 ± 0.5 mV/decade over the range 1.0 x 10-6 to 1.0 Mat pH 3.0-10.0. Thelimit of detection was 2.4 x 10-7 M. The influences of membrane composition, the pH of the t...