The impact of land use change on potential evapotranspiration is a hot issue in hydrology and other related fields. Based on the meteorological data of central Guizhou Province from 1995 to 2015, we estimated the potential evapotranspiration (ET0) using Penman-Monteith equation and analyzed the spatio-temporal characteristics of ET0 in this region and the impact of different land use types on ET0 using the land use data from 1995 to 2015. The results show that the ET0 of central Guizhou from 1995 to 2015 showed an overall upward trend, with a significant spatial distribution pattern, it decreased from southeast to northwest. The land use structure in central Guizhou changed significantly over the period of 1995-2015, the woodland and construction land were mainly increasing, whereas the grassland and cultivated land are mainly decreasing. Different land use types had different ET0, with the ET0 of woodland being the largest, followed by that of cultivated land, grassland, water area and construction land, and unused land had the smallest ET0. The ET0 increased when parts of the grassland and cultivated land were transferred to woodland, but it decreased when parts of woodland, grassland and cultivated land were transferred to construction land and unused land. This indicates that ET0 changes simultaneously with the change of land use. This study on evapotranspiration can shed some light on the understanding of regional hydrological process and water resources management.