Nd3+ fluorescence of LiNdP4O12 nanocrystals was observed upon subresonant excitation with the 1064 nm wavelength of LD laser at room temperature. It was found that the F-4(3/2) fluorescence was temperature dependent. The distribution of intensities between the respective Stark sublevels of F-4(3/2)(R-1, R-2) -> I-4(9/2)(Z(1-5)) transition band was substantially different in comparison to the resonant excitation with the 514 nm line of argon laser. A mechanism of subresonant Nd3+ fluorescence was investigated. It was concluded that it is associated with a high thermal population of I-4(11/2) term stimulated by cooperative Nd-Nd interion interaction. (C) 2013 Elsevier B.V. All rights reserved.