We investigated the electrochemical behavior of hemoglobin by glassy carbon electrode modified with Mn(2)O(3)-Ag nanofibers. The Mn(2)O(3)-Ag nanofibers were used as facilitator electron transfer between Hb and glassy-carbon-modified electrode. The Mn(2)O(3)-Ag nanofibers are studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The hemoglobin showed a quasireversible electrochemical redox behavior with a formal potential of -49 mV (versus Ag/AgCl) in 0.1 M potassium phosphate buffer solution at pH 7.0. The designed biosensor possesses good stability and reproducibility and achieves 95% of the steady-state current in less than five seconds.