Ag+ doping TiO2 nanofibers were prepared by in-situ and immersion methods (named as SI-TiO2 and IM-TiO2 nanofibers, respectively). This paper assesses the effects of the two different doping methods on the material properties. Results show that the two kinds of nanofibers with the diameter of about 20 nm are micron-sized length, and covered by nano-balls of Ag2O with the diameter of 2-5 nm. Compared to IM-TiO2 nanofibers, the SI-TiO2 nanofibers have fewer Ag2O particles. Thus, the photo-catalytic activity of IM-TiO2 nanofibers is higher than SI-TiO2 nanofibers, which is also proved in photo-catalysis experiment (the degradation ratio of IM-TiO2 catalyst is 100%. and the degradation ratio of SI-TiO2 catalyst is 95%). (C) 2010 Elsevier Ltd. All rights reserved.