  We summarize the current theoretical and experimental status of the spectral
changes of vector mesons ($\rho$, $\omega$, $\phi$) in nuclear medium. Various
approaches including QCD sum rules, effective theory of hadrons and bag models
show decreasing of the vector meson masses in nuclear matter. Possibility to
detect the mass shift through lepton pairs in $\gamma-A$, $p-A$ and $A-A$
reactions are also discussed.
