Mountain cloud forest is unique yet vulnerable ecosystem under climate change due to its high sensitivity to hydroclimate. Here we reconstructed precipitation for the past 480 years (AD 1533-2012) in eastern Taiwan and showed that mountain cloud forest is exposing to the lowest level of rainfall and the highest frequency of extreme events for the past three decades. Specifically, we obtained stable oxygen isotope ratios (δ18O) in tree rings of long-lived Chamaecyparis formosensis. The δ18O chronology showed significant correlations with May-June precipitation, mean relative humidity, and April-September cloud cover, and thus allowed the robust climate reconstruction.