CuY zeolite is a promising catalyst for oxidative carbonylation of methanol to dimethyl carbonate (DMC). In this work, auto-reduction at high temperature and vapor-induced reduction were comparatively investigated to activate the CuY precursors. XPS, XRD as well as CO adsorption demonstrated that methanol as reduction agent can achieve a high proportion of Cu(I) and avoid the formation of Cu(0) as far as possible, which is responsible for the enhanced DMC yield.