In order to develop new-typed up-conversion luminescent nanomaterials with peculiar morphology, LaOI:Yb3+/Ho3+ nanostructures, including nanofibers and nanobelts, were synthesized by electrospinning combined with a double-crucible iodination technique using NH4I as iodine source for the first time. X-ray powder diffraction (XRD) analysis indicates that LaOI:Yb3+/Ho5+ nanostructures are tetragonal phase with space group of P4/nmm. Scanning electron microscope (SEM) analysis and histograms reveal that diameter of LaOI:Yb3+/Ho3+ nanofibers and the width of LaOI:Yb3+/Ho3+ nanobelts are respectively 147.48 +/- 17.50 nm and 3.54 +/- 0.22 mu m, and the thickness of the nanobelts is 186 nm. Under the excitation of a 980-nm diode laser (DL), LaOI:Yb3+/Ho3+ nanostructures emit strong green and red up-conversion emissions centering at 541 nm and 655 nm, respectively attributed to F-5(4)/S-5(2) -> 518 and F-5(5) -> I-5(8) energy levels transitions of Ho3+. The up-conversion luminescent mechanism and the formation mechanism of LaOI:Yb3+/Ho3+ nanostructures are also proposed. (C) 2014 Elsevier B.V. All rights reserved.