We　review　the　current　state-of-the-art　of　bioluminescence　tomography　(BLT)　imaging,　which　is　an　emerging　technique　for　monitoring　and　assessment　of　biological　processes　in　vivo.　The　aim　of　BLT　is　to　reconstruct　3-D　distribution　of　the　internal　bioluminescent　source　using　boundary　measurements　acquired　by　a　BLT　imaging　system.　Thus,　BLT　becomes　a　task　of　solving　an　inverse　problem　with　an　appropriate　photon　propagation　model.　In　this　paper,　we　discuss　recent　advances　in　models　of　photon　transport,　and　review　in　detail　the　current　techniques　for　BLT　reconstructions.　Specifically,　we　consider　the　reconstruction　algorithms　based　on　the　permissible　source　region　strategy,　and　multispectral　and　regularization　techniques.　The　progress　in　the　BLT　imaging　system　is　also　briefly　introduced.　Finally,　future　challenges　are　also　discussed.