  In this paper, we study different cases of the charged rotating BTZ black
hole with reference to their horizons. For the existence of these cases
conditions on mass, charge and angular momentum of the black hole are obtained.
It is also shown that the Einstein field equations for the charged rotating BTZ
black hole at the horizon can be expressed as first law of thermodynamics,
$dE=TdS+\Omega dJ+\Phi dq+P_{r}dA$.
