Photodissociation dynamics of nitrobenzene molecular ion has been investigated on a nanosecond time scale by mass-analyzed ion kinetic energy spectrometry. Photodissociation has been found to occur through various reaction channels. Three dissociation channels to C6H5O+, C6H5+, and NO+ have been observed together with a consecutive dissociation to C5H5+ via C6H5O+ The photodissociation rate constant of the molecular ion and the kinetic energy release distributions in each channel have been determined. The rate constant of the second step of the consecutive reaction has been determined in real time also. It has been found that the direct bond cleavage to C6H5+ occurs in competition with the rearrangement processes to C6H5O+ and NO+ on a nanosecond time scale. Statistical theories have been used to gain insight into the dynamics of the reactions.