  Hawking radiation is one essential property of quantum black hole. It results
in the information loss paradox, and give important clue to the unification of
quantum mechanics and general relativity. In the previous works, the boundary
scalar field on the horizon of black holes were used to give the microstates of
BTZ black holes and Kerr black holes. They are account for the
Bekenstein-Hawking entropy. In this paper, we show that the Hawking radiation
can also be derived from those scalar fields. Actually the Hawking radiation
are superposition of thermal radiation of right/left sector at different
temperatures. We also discuss the impact on the information loss paradox.
