  The existence and uniqueness of two dimensional steady compressible Euler
flows past a wall or a symmetric body are established. More precisely, given
positive convex horizontal veloicty in the upstream, there exists a critical
value $\rho_{cr}$ such that if the incoming density in the upstream is larger
than $\rho_{cr}$, then there exists a subsonic flow past a wall. Furthermore,
$\rho_{cr}$ is critical in the sense that there is no such subsonic flow if the
density of the incoming flow is less than $\rho_{cr}$. The subsonic flows
possess large vorticity and positive horizontal velocity above the wall except
at the corner points on the boundary. Moreover, the existence and uniqueness of
a two dimensional subsonic Euler flow past a symmetric body are also obtained
when the incoming velocity field is a general small perturbation of a constant
velocity field and the density of the incoming flow is larger than a critical
value. The asymptotic behavior of the flows is obtained with the aid of some
integral estimates for the velocity field and its far field states.
