Hadron properties in nuclear medium and their impacts on observables

The effect of changes in hadron properties in a nuclear medium on physical observables is discussed. Highlighted results are, (1) hypernuclei, (2) meosn-nuclear bound states, (3) $K$-meson production in heavy ion collisions, and (4) $J\mathrm{/}\mathrm{\Psi }$ dissociation in a nuclear medium. In addition, results for the near-threshold $\omega$- and $\varphi$-meson productions in proton proton collisions are reported.