Monodispersed Fe3O4/polypyrrole (PPy) hollow particles were synthesized via controllable in-sire deposition and polymerization techniques using poly(styrene-co-acrylic) (PSA) latex as template.Field-dependent magnetization plot illustrates that the capsules are superparamagnetic at 300 K.FTIR spectrum confirms that the myoglobin (Mb) molecule adsorbed on the surface of Fe3O4/PPy hollow particle essentially retains its native structure.Furthermore,direct electrochemistry of Mb can be realized on Fe3O4/PPy capsules modified pyrolytic graphite disk electrode,which indicates that the magnetic conductive polymer capsules can promote the electron transfer of protein.