In theory, a Rebel can use any lens made for Canon EOS. The pro bodies that do not have an APS-C size sensor can't use any lens designed for APS-C (e.g. You can't use an "EF-S" lens, but you can use any "EF" lens (as well. The specialty lenses... MP-E and TS-E)Here's the catch: Canon (and Nikon is the same) do not offer assistance to 3rd party lens makers. Tamron, Tokina, Sigma, etc all have to revse engineer the interface. They usually test the camera that are out when the lens was originally designed, but sometimes a new body is released and they find the lens doesn't work with it. Also... Tamron makes lenses to work with Canon, Nikon, and others. So you'd need to know which version of the lens you have. A lens designed for a Canon will not work on a Nikon.