  Suppose that $X$ and $Y$ are quasiconvex and complete metric spaces, that
$G\subset X$ and $G'\subset Y$ are domains, and that $f: G\to G'$ is a
homeomorphism. In this paper, we first give some basic properties of short
arcs, and then we show that: if $f$ is a weakly quasisymmetric mapping and $G'$
is a quasiconvex domain, then the image $f(D)$ of every uniform subdomain $D$
in $G$ is uniform. As an application, we get that if $f$ is a weakly
quasisymmetric mapping and $G'$ is an uniform domain, then the images of the
short arcs in $G$ under $f$ are uniform arcs in the sense of diameter.
