Chemical reactivity studies of the organotin(IV) carboxylates diphenyltin(IV) di-4-amino-benzoate (1) and triphenyltin(IV) 4-aminobenzoate (2) were conducted using cyclic voltammetry. Then, their antioxidant activities were tested by the 2,2-diphenyl-1-picrylshydrazyl (DPPH) method. Cyclic voltammetry was used to determine the kinetic constants of compounds 1 and 2 for the forward chemical reaction (kf). The constant values of the chemical reaction rate of 1 and 2 on cyclic voltammogram by experiment were obtained by comparing with the values from digital simulation methods obtained using Polar software 5.8.3. The results demonstrated that the constant value of the rate of the subsequent chemical reaction is a function of the rate of its potential (slope = kf/i); that is, 6.481 and 6.069 1/V for 1 and 2, respectively. The type of chemical reaction mechanism that occurs around the surface of the working electrode follows reaction mechanism of electrochemical reaction is quasi reversible and chemical reaction is irreversible (EqCi). The antioxidant activities of compounds 1 and 2 produced IC50 values of 5.91 and 12.57 ig/mL, respectively. These results indicate that both compounds are active as antioxidants. However, their antioxidant activities were lower than that of ascorbic acid, which has an IC50 value of 0.66 ig/mL.