  We discuss the impact of charged massive particle big bang
nucleosynthesis(CBBN) to explore the nature of the reheating of the Universe in
the case that a new extremely long-lived charged massive particle(CHAMP)
exists. If the mass of the CHAMP is within collider reach and it's lifetime is
longer than $10^4$sec, the comparison between the CBBN prediction and observed
$^6$Li abundances may indicate nonstandard reheating in the early Universe
without relying on details of the decay properties. Even if the CHAMP mass is
outside the reach of colliders, the cosmological considerations may provide a
nontrivial hint for the existence of such very heavy long-lived CHAMPs from the
late Universe if the daughter particles are the dominant component of the
present dark matter. We consider a low reheating temperature model as an
example of the nonstandard reheating scenarios.
