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The Central Asian dryland (CAD) and East Asian dryland (EAD) are typical drylands in the globe. They are characterized by less precipitation, with vulnerable and sensitive ecosystems. Although they are located in the heart of continent, precipitation in these regions has opposite patterns on the multi-decadal time scale. In this study, we focus on different responses of precipitation changes in these drylands and related drought to different phases of the Atlantic Multidecadal Oscillation (AMO) on the multi-decadal time scale. We show that less precipitation in the CAD and more precipitation in the EAD were always associated with a positive AMO phase, which was caused by the weakened westerly and simultaneous enhancement of vertically integrated water vapor from the Indian Ocean and western Pacific. Such precipitation pattern was accompanied by a drying (wetting) phase of self-calibrating Palmer's drought severity index in the CAD (EAD), which further contributed to a worse (better) ecology in the CAD (EAD). This explains why the positive AMO phase in recent decades starting from 2000 made a positive contribution to the drying (wetting) arid region in the CAD (EAD).