  We perform a systematic study of outflow in the narrow-line region (NLR) of
active galactic nuclei (AGNs) at $z\sim0.4-0.8$ basing upon a large sample of
$\sim900$ quasars at $z\sim 0.4-0.8$. The sample is extracted from the Sloan
Digital Sky Survey by mainly requiring 1) the g-band magnitude is brighter than
19 magnitude; and 2) the [OIII]$\lambda5007$ emission line has a
signal-to-noise ration larger than 30. Profiles of multiple emission lines are
modeled by a sum of several Gaussian functions. The spectral analysis allows us
to identify 1) a prevalence of both [OIII]$\lambda5007$ line blue asymmetry and
bulk velocity blueshift of both [NeIII]$\lambda3869$ and [NeV]$\lambda3426$
lines, when the [\ion{O}{2}]$\lambda3727$ line is used as a reference. The
velocity offset of [\ion{O}{3}]$\lambda5007$ line is, however, distributed
around zero value, except for a few outliers. 2) not only the significant
[OIII]$\lambda5007$ line asymmetry, but also the large bulk velocity offsets of
[NeIII]$\lambda3869$ and [NeV]$\lambda3426$ emission lines tend to occur in the
objects with high $L/L_{\mathrm{Edd}}$, which is considerably consistent with
the conclusions based on local AGNs. With three $M_{\mathrm{BH}}$ estimation
methods, the significance level of the trend is found to be better than
$2.9\sigma$, $3.2\sigma$ and $1.8\sigma$ for [OIII], [NeIII] and [NeV],
respectively. \rm After excluding the role of radio jets, the revealed
dependence of NLR gas outflow on $L/L_{\mathrm{Edd}}$ allows us to argue that
the pressure caused by the wind/radiation launched/emitted from central
supermassive black hole is the most likely origin of the outflow in these
distant quasars, which implies that the outflow in luminous AGNs up to $z\sim1$
have the same origin.
