The cation and anion products of the reactions between lead clusters produced in the laser ablation and the benzene molecules seeded in argon were studied by high-resolution reflectron time-of-flight mass spectrometer (RTOFMS). The dominant cation products were Pb/benzene association complexes, while the dominant anion products were dehydrogenated species, [PbmCn](-), [PbmCnHk](-), etc. One important intermediate distinguished in the anion reactions was [Pb-m(C6H5)](-) product. Two conspicuously different and independent reaction mechanisms were proposed for lead cluster cations and anions, respectively.