  Yang-Mills theory with flavor quarks in the dS${}_4$ is studied through the
dual supergravity in the AdS${}_5\times S^5$ background with non-trivial
dilaton and axion. The flavor quarks are introduced by embedding a probe D7
brane. We find that the dynamical properties of YM theory in the dS${}_4$ are
similar to the case of the finite temperature theory given by the 5d
AdS-Schwarzschild background. In the case of dS${}_4$, however, contrary to the
finite temperature case, the gauge field condensate plays an important role on
the dynamical properties of quarks. We also give the quark-antiquark potential
and meson spectra to find possible quark-bound states. And we arrive at the
conclusion that, while the quarks are not confined in the dS${}_4$, we could
find stable meson states at very small cosmological constant as expected in the
present universe. But there would be no hadrons at early universe as in the
inflation era.
