  In this paper we discuss phase transition of the charged topological dilaton
AdS black holes by Maxwell equal area law. The two phases involved in the phase
transition could be coexist and we depict the coexistence region in $P-v$
diagrams. The two-phase equilibrium curves in $P-T$ diagrams are plotted, the
Clapeyron equation for the black hole is derived, and the latent heat of
isothermal phase transition is investigated. We also analyze of the parameters
of the black hole that have an effect on the two phases coexistence. The
results show that the black hole may go through a small-large phase transition
similar to those of usual non-gravity thermodynamic systems.
