In order to analyze the response to drought stress of the five species of Catalpa Scop.， to provide theoretical basis for the selection on drought-resistant breeding and cultivation of drought-resistant tree species of Catalpa Scop.， the C.speciosa， C.fargesii f.duclouxii， C.fargesii， C.ovata， and C.bungei were selected as materials， and cultivated for 50 days under the water conditions of 700 and 400 mL respectively， and seedling height， diameter， leaf water potential， relative content of chlorophyll， chlorophyll fluorescence parameters， and specific leaf weight were measured respectively. The membership function method was used to comprehensively evaluate drought resistance. The results showed that the C.bungei grew best but the C.ovata was relatively poorest under the two water conditions. Under drought stress， except for the C.speciosa， the leaf water potential（ΨL） of all other species decreased， and the maximum stomatal conductance（Gs） increased respectively. The relative chlorophyll content（SPAD） of different species increased under drought stress. The maximum light energy conversion efficiency（Fv/Fm） of photosystem Ⅱ of each species increased under drought stress， except for C.fargesii f.duclouxii and C.bungei. In addition to C.fargesii， the specific leaf weight（LMA） of other tree species increased under drought stress. The results of comprehensive drought resistance using the membership function method were gray C.fargesii>C.ovata>C.fargesii f.duclouxii>C.bungei>C.speciosa. The results showed that different species of Catalpa Scop. have different drought resistance. Comprehensive analysis showed that the drought resistance of C.bungei and C.fargesii were strong， and that of C.fargesii f.duclouxii and C.ovata were the second， and that of C.speciosa was the worst.
%U https://bbr.nefu.edu.cn/EN/10.7525/j.issn.1673-5102.2021.01.006