Transient radiative transfer in a 2-D finite cylindrical medium with collimated pulse irradiation and a large mean free path fbr scattering is considered thoroughly. Highly accurate solutions of integral equation for the transient radiative transfer reveal that the radiative energy of the medium core is less than the radiative energy of the medium boundary, after the attenuated pulse irradiation has passed through the medium. The distinction between the extraordinary results of the above case and the results of other cases is examined. It is found that influence of the decrease rate of radiative energy with the passage of time is larger than that of the extinction decay of the radiative intensity along a propagation path for transient radiative transfer in a 2-D medium with a large mean free path for scattering. Moreover, scattering coefficient and geometric size are the major factors determining the spatial distribution type of scattered radiation energy at large time and the temporal evolution of the spatial distribution type of radiation energy.