We focus on the thermodynamic behavior of Polytropic gas as a candidate for dark
energy (DE). We use the general arguments of thermodynamics to investigate its properties
and behavior. We find that a Polytropic gas can exhibit the DE-like behavior.
It also may be used to simulate a fluid with zero pressure at the small volume and
high temperature limits. Briefly, our study shows that this gas may be used to describe
the universe expansion history from the matter dominated era to the current accelerating
era. By applying some initial conditions to the system, we can establish a relation
between the Polytropic gas parameters and the initial conditions. Relationships with
related works have also been addressed.