Bookmarks in Firefox re-install

I want to know that if I uninstall Firefox and then re-install than will my bookmarks be reloaded automatically?

I'm pretty sure it wont, but then I'm not that familiar with doing anything like that, although it does make back up's by default, I couldn't say if these would remain after uninstalling it, safest answer unless someone knows better is to make a manual back up, then when reinstalled you can add them back again, I'm not saying theres not a better way, but logically it should be the safest way to go, hope it helps.
Backing up and restoring bookmarks

Bookmarks, history, etc are in your profile directory which is not deleted when you uninstall FireFox (or Mozilla or SeaMonkey or Netscape). When you reinstall they may not be used though as a new profile will be created, so you will have to copy them from the old profile location to the new one.

Good info on this here:
Transferring data to a new profile
Working with FireFox profiles