Hello Nancy,
      The FSL 5.0.8 packages can be found in:

http://fsl.fmrib.ox.ac.uk/fsldownloads/oldversions/

Hope this helps,
Matthew

Hi folks:
       I am uregnt to looking forward to your help about how to download the 5.0.8 version of FSL.thanks a lot!
All the best
Nancy Li