Abstract: The chlorophyll fluorescence parameters, e.g. Fr/Fm Fr/Fm, φPSⅡ, qp, NPQ, ETR, for four type of Catalpa spp. were determined and analysed using chlorophyll fluorescence kinetics technology under drought stress. The results showed that the Fr/Fm and qp had the trend of decrease--increase --decrease with the increase of drought stress. It indicated that photoinhibition took place at the first stage of drought stress, then the tree adjusted itself and the reaction center began to open and reduce the photoinhibition. An the end, the photoinhibition began to increase. The results of Fr/Fm、NPQ,ETR,φPSⅡ increase in the early, and reduce in the later. The results showed that the tree could adapt the adversity and the plant had protection mechanism. There were great different of the capability to react to drought stress for four type of Catalpa. According to Fr/Fm, the ability of drought resistance of four type of Catalpa spp. was ’Nanyang’ ,’Jinsi’ , ’Yuanjichangguo’, Catalpa bungei.