A simply and sensitively electroanalytical method for determination of bisphenol A (BPA) using poly(amidoamine) (PAMAM) and Fe sub(3)O sub(4) magnetic nanoparticles modified glassy carbon electrode (GCE) was presented. Compared with bare electrode, PAMAM-Fe sub(3)O sub(4) modified electrode not only significantly enhanced the oxidation peak current of BPA, but also lowered the oxidation overpotential, suggesting that the modified electrode can remarkably improve the determining sensitivity of BPA. Factors influencing the detection processes were optimised and kinetic parameters were calculated. Under the optimal conditions, the oxidation current increased linearly with increasing the concentration of BPA in the range of 1 x 10 super(-8)-3.07 x 10 super(-6) M with the correlation coefficient of 0.9996 and the detection limit of 5 x 10 super(-9) M. The current reached 95% of the steady-state current within about 6 s. The proposed method was successfully applied to determine BPA in milk samples and satisfactory results were obtained.