We reexamined the vibronic structure of the jet-cooled 2,6-dimethylbenzyl radical that was generated from 1,2,3-trimethylbenzene seeded in a large amount of inert carrier gas helium using a pinhole-type glass nozzle in a corona excited supersonic expansion, from which the vibronically resolved emission spectrum was recorded with a long path double monochromator in the visible region. The spectrum exhibited bands arising from not only the D-1 -> D-0 transition but also the D-2 -> D-0 transition, in which transitions the accurate electronic energies of the D-2 and D-1 states and the revised vibrational mode frequencies in the ground electronic state were obtained by comparison with those from the known data of the precursor and an ab initio calculation.