  In this paper, we present a preliminary study of $CP$ violation effect of
$K^{0}-\bar{K}^{0}$ system in $J/\psi$ decay. The $CP$ violation parameters
$\eta_{+-}$ and $\eta_{00}$ as well as their corresponding phase $\phi_{+-}$
and $\phi_{00}$ can be determined by the difference of the time-dependent decay
rates between $K^{0}$ and $\bar{K}^{0}$ produced from $J/\psi \rightarrow
K^{-}\pi^{+}K^{0} + c.c.$ processes. We investigate the precisions of the
measurements of the CP violation effect at the Super Tau-Charm facility(STCF),
a $e^{+}e^{-}$ collider with a peak luminosity of $0.5\times10^{35}\
\rm{cm}^{-2}\rm{s}^{-1}$. The parameters $\eta_{+-}$ and its phase $\phi_{+-}$
can be measured at a relative precision of $1 \times 10^{-3}$, which the
statistical accuracy will be several times better than that of the existing PDG
average values.
