This paper covers our recent study of the quenching processes of I2(B3Πo+u) at high vi-brational level v′= 62. In the experiments, quenching rate constants of I2* with itself and with other molecules (He, Ar, Kr, H2, CO, N2, O2, CH4, NH3, C2H6) were determined, and it was found that in the collision process of I2* and NH3, the formation of the metastable complex (I2*…NH3) might be one of the major processes for fluorescence quenching. The quenching efficiency of the polar molecule, CO, is larger than other molecules, such as the :isoelectronic molecule, N2, showing that intermolecular dipole-induced dipole interaction may play an important role in enhancing the molecular quenching. More important, the theory for collision-induced dissociation (CID) proposed in paper 1 can satisfactorily model the experimental results, indicating strongly that in such high vibrational level, collision-induced direct dissociation is the dominant path.