  We present the first results of searches for axions and axion-like-particles
with the XENON100 experiment. The axion-electron coupling constant, $g_{Ae}$,
has been probed by exploiting the axio-electric effect in liquid xenon. A
profile likelihood analysis of 224.6 live days $\times$ 34 kg exposure has
shown no evidence for a signal. By rejecting $g_{Ae}$, larger than $7.7 \times
10^{-12}$ (90\% CL) in the solar axion search, we set the best limit to date on
this coupling. In the frame of the DFSZ and KSVZ models, we exclude QCD axions
heavier than 0.3 eV/c$^2$ and 80 eV/c$^2$, respectively. For
axion-like-particles, under the assumption that they constitute the whole
abundance of dark matter in our galaxy, we constrain $g_{Ae}$, to be lower than
$1 \times 10^{-12}$ (90\% CL) for mass range from 1 to 40 keV/c$^2$, and set
the best limit to date as well.
