  Multi wavelength observations of Cassiopeia A (Cas A) have provided us with a
strong evidence for the presence of circumstellar material surrounding the
progenitor star. It has been suggested that its progenitor was a massive star
with a strong mass loss. But, despite the large amount of observational data
from optical, IR, radio and x-ray observations, the identity of Cas A
progenitor is still elusive. In this work, we compute stellar and circumstellar
numerical models to look for the progenitor of Cas A. The models will be
compared with the observational constraints. We have computed stellar evolution
models to get time-dependent wind parameters and surface abundances. We have
chosen a set of probable progenitor stars, with initial masses of 23, 28, 29,
30 and 33 \Mo, with mass loss. The derived mass loss rates and wind terminal
velocities are used to simulate the evolution of the circumstellar medium. Our
stellar set gives distinct SN progenitors: RSG, luminous blue super giants
(LBSGs) and Wolf-Rayet (WR) stars. The 23 \Mo star explodes as a RSG in a $\rm
\rho \sim r^{-2}$ dense, free streaming wind surrounded by a thin, compressed,
RSG shell. The 28 $\Mo$ star explodes as a LBSG, and the SN blast wave
interacts with a low density, free streaming wind surrounded by an unstable and
massive ''RSG+LBSG'' shell. Finally, the 30 and 33 \Mo stars explode as WR
stars surrounded by fast, WR winds that terminate in highly fragmented ''WR+RSG
shell''. We have compared the surface chemical abundances of our stellar models
with the observational abundances in Cas A. The abundance analysis shows that
the progenitor was a star with an initial mass of the order of 30 \Mo, while
the hydrodynamical analysis favors progenitors of initial masses around 23.
