The 1(3) Delta(g) state of Na-2 has been studied extensively by both filtered fluorescence and ionization detection and analyzed by both Dunham-type expansion and near-dissociation expansion (NDE) models in the analysis. Our observations have covered 99.998% of the potential well depth with the outermost Rydberg-Klein-Rees (RKR) turning point at 28.02 Angstrom. NDE analysis gives T-e=28.032.468 (+/-0.021) cm(-1), D-e=7162.436 (+/-0.021) cm(-1), and R(e)=3.46381 (+/-0.00028) Angstrom. Significant long-range behavior in the near dissociation levels has been observed. Fitting of the RKR turning points gives the long-range coefficients C-5=1.388 (+/-0.031)x10(6) cm(-1) Angstrom(5) and C-6=0.4008(+/-0.0046)X10(8) cm(-1)Angstrom(6). These newly observed results show reasonable agreement 6 with recent theoretical calculations.