Magnetotactic bacteria can form uniform nanometer sized magnetic particles(megnetosomes)within the bacterial cells and each particle is enveloped in a membrane.The purified magnetosomes are compatible and less toxic to SD rat.It may be used as a carrier to link with certain antibiotics and larger molecular compounds for treatment of tumors.Here we described the properties of the magnetosnmes and the strategies for linking drugs.We also discussed the possibility to establish the system of targeted therapy for cancers using drug-loaded magnetosumes.