The talk starts with a brief description of CLEO detector and expands on 
its particle identification capabilities. Using information from the
ring imaging Cherenkov detector (RICH), the specific ionization in the
drift chamber, the Crystal Calorimeter (CC) and the muon chamber we are
able to discriminate photons, electrons, muon, pions, kaons and protons
up to the endpoint of B meson decays. As an example we present the
determination of the inclusive fractional yields of charged particles
from B mesons in Upsilon(4S) decays.