The mixed MoO3-ZnO catalyst was expected to reveal the new function as a catalyst. The catalyst was characterized by XRD, ESR, XANES and so on. We found that the MoO3-ZnO catalyst was effective for isomerization and metathesis of l-butene. The defects with the anion vacancy were formed on ZnMoO3 and MoO3. They gave the acidic sites and acted as the active site for isomerization of 1-butene. Also, the distorted MoO2 was formed on the surface and acted as the active site for the metathesis.