【Objective】A comparison of drought resistance was made between two fast growing species in South China， Eucalyptus urophylla× E. grandis（EE for abbr.） and bamboo willow （BW for abbr.）.【Method】Effective quantum yield of PSⅡ photochemistry（Yield）， apparent electron transport rate（ETR）， the photochemical quenching （qP ）， the non-photochemical quenching （qN）， minimal fluorescence（F₀）， maximal fluorescence（F_m）， potential photochemical efficiency of PSⅡ（F_v/F_m） in EE and BW were tested by OS5P pulse modulated chlorophyll fluorometer under drought stress. 【Result and conclusion】 Yield， ETR， qP， F_m and F_v/F_m all declined during the drought. At day 24 after treatment， ETR declined by 48.02% and 25.12% EE and BW， respectively. qN and F₀ in the 2 species increased. qN in BW rose by 217.59%， which was significantly higher than that in EE （146.40%， P<0.05）. The relative increment in F₀ in BW （49.11%） was smaller than that in EE （92.03%） at the end of the drought treatment. Correlation analyses were made concerning chlorophyll fluorescence characteristics and soil water content. In both species， ETR showed a significant positive correlation with soil water content （P<0.01）. F₀ in EE showed a significant negative correlation with soil water content （P<0.01）. F_m and F_v/F_m of BB and soil water content showed a significant positive correlation （P<0.01）. These results indicate that correlations existe among chlorophyll fluorescence characteristics in two species under drought. BW has greater drought resistance than EE as revealed by chlorophyll fluorescence characteristics.