  A sterile neutrino at GeV mass scale is of particular interest in this work.
Though not take part in neutrino oscillation, the sterile neutrino can induce
flavor violating semileptonic and leptonic decay of $K, D$ and $B$ mesons. We
calculated a box diagram contribution in these processes. By making use of
current experiment limit of lepton flavor violating decays $M^+_h\to
M_l^+\ell_1^+\ell_2^-$ and $M^0\to \ell_1^-\ell_2^+$, we explore the allowed
parameter space of $U_{e4}$ and $U_{\mu 4}$ in different mass ranges. Generally
speaking, both channels give a limit to the product of $U_{e4}$ and $U_{\mu
4}$. When sterile neutrino mass is located in between pion and kaon mass,
$K^+\to \pi^+ e^{\pm}\mu^{\mp}$ gives the strongest constraint while $B^+\to
\pi^+ e^{\pm} \mu^{\mp}$ provides the dominated constraint when its mass in
between of kaon and B meson. If sterile neutrino is even heavier than B mesons,
the $B^0_s\to \mu^{\pm} e^{\mp}$ experiment which is performed at LHCb gives
the strongest constraint.
