Laser multiphoton ionization mass spectra of Fe (CO) 5 were studied at 355 nm, 632 nm and 355nm+532nm, with a supersonic molecular beam and a time-of-flight mass spectrometer. Our experimental results show the resonance enhancement in the two-color laser multiphoton ionization of Fe(CO)5. We have estimated the cross-section and the lifetime of ion-molecule reaction between Fe+ and Fe (CO) 5, and the dissociation lifetimes of photo-excited Fe(CO)5 and Fe(CO)by examining the broading and structure of ion peaks in the time-flight mass spectra.