The algorithm for the reconstruction of muon pairs produced in heavy ions collisions and detected in the CMS barrel part is presented. With an efficiency of 66% for the Upsilon( 1S)-decay dimuons in the case of central Pb-Pb collisions it enhances the Signal/Background by a factor 6 in the pseudorapidity region -0.8<eta<0.8. For the 0.8<|eta|<1.5 evaluated efficiency is 45% for Upsilon into mu+mu- and 15% for uncorrelated muons from pi/K decays