The thermodynamic and kinetic parameters (the formal potential, E degrees＇, the standard rate constant, k degrees, and the cathodic transfer coefficient, alpha(c)) of the reduction of oxygen to superoxide ion (O-2(-)) at glassy carbon electrode in quinoline and isoquinoline solutions have been evaluated using cyclic and normal pulse voltammetry. Tetrabutylammonium perchlorate (0.1 M) was used as supporting electrolyte. The obtained values of E degrees＇ (V vs. Ag/AgClO4 (0.01 M)), k degrees (cm s(-1)) and alpha(c) are as follows: -0.85 +/- 0.01, (6.9 +/- 0.5) x 10(-3) and 0.44 +/- 0.05 in quinoline, and -1.00 +/- 0.01, (3.4 +/- 0.3) x 10(-3) and 0.42 +/- 0.03 in isoquinoline. They are compared with the previous data obtained for the O-2/O-2(-) couple in the commonly used aprotic solvents, demonstrating that quinoline and isoquinoline are newly included in solvents which are suitable for examining the electrode reaction of O-2/O-2(-) couple as well as various reactivities of O-2(-).