Abstract: ObjectiveTo apply molecular typing methods for detection of Legionella pneumophila isolated from the air-conditioning cooling tower.MethodsThe amplification and sequencing of macrophage infectivity potentiator(MIP) gen and pulsed-field gelelectropho resis(PFGE)were carried out to calssify 48 Legionella pneumophila strains.ResultsBased on MIP method the 48 strains were classified into 5 different patterns:L.pnuemophile-phil-1,L.pnuemophile-phil-sg 3,L.pnuem ophile-phil-D-15,L.pnuemophile-phil-sg 10,L.pnuemophile-phil-97-2898.The L.pnuemophile-phil-1 was dominant(60.4%).PFGE method showed 23 different patterns without dominant pattern.ConclusionThe PFGE method has much higher discriminatory power and greater potential use for epidemio logic studies of L.pnuemoplila.