Magnetic　nanofluid　hyperthermia　(MNH)　damages　malignant　cells　by　the　heat　generated　by　magnetic　nanoparticles　(MNPs)　exposed　to　an　alternating　magnetic　field　during　therapy.　The　key　point　for　magnetic　hyperthermia　is　to　maintain　the　treatment　temperature　to　a　safe　range　for　bio-tissue,　in　which　malignant　tissue　will　be　damaged　due　to　its　higher　heat　sensitivity　but　not　the　healthy　tissue.　However,　the　therapeutic　system　for　MNH　should　be　a　nonlinear　one　since　the　treatment　temperature　is　generally　determined　by　many　certain　and　uncertain　factors,　which　result　in　the　difficulty　to　modulate　the　temperature　to　a　specific　range　in　a　practical　application.　This　study　proposes　a　control　method　for　an　MNH　system　by　introducing　a　proportional-integral-derivative　(PID)　control　algorithm　and　dynamically　optimizes　the　PID　coefficients　for　the　proposed　system　by　considering　simulated　annealing　(SA)　algorithm　during　therapy.　The　treatment　temperature　distribution　for　bio-tissue　is　obtained　by　solving　an　improved　Pennes　bio-heat　transfer　equation　using　finite　element　method　(FEM).　The　simulation　results　demonstrate　that　the　proposed　control　system　can　effectively　modulate　the　power　dissipation　for　MNPs　and　further　exactly　regulate　the　transient　treatment　temperature　to　an　expected　value.　In　addition,　this　proposed　system　can　also　automatically　adapt　to　different　cases　during　therapy,　in　which　the　nanofluid　concentration　distribution　inside　tumor　region　changes　with　nanofluid　injection　strategy.　©　1963-2012　IEEE.