X-ray diffraction analysis, emission under 808 nm excitation by laser diode, and fluorescence lifetime were investigated at room temperature on a series of Nd3+ doped PbWO4 (PWO) single crystals grown by modified Bridgman method. By using Judd-Ofelt (J-O) theory, the phenomenological intensity parameters (Omega(1) were calculated Omega(2) = 7.53 x 10(-20) cm(2), Omega(4) = 3.15 x 10(-20) cm(2), Omega(6) = 3.06 x 10(-20) cm(2). On the base of the Omega(1) calculation, the intermanifold luminescence branching ratios beta(JJ'), irradiative lifetime of the F-4(3/2) level, the absorption and emission cross section were calculated. Nd3+ doped PWO single crystal at a level 2.0 at.% shows efficient emission (950-1100 nm), whose 1.06 mum fluorescence was enhanced and fluorescence lifetime was increased after annealing treatment. The annealing mechanism was discussed. (C) 2003 Elsevier Science Ltd. All rights reserved.