Abstract: In this study, the effect on growth and drought tolerance of the succulent xerophyte Zygophyllum xanthoxylum under drought stress of a Na compound fertilizer that contains appropriate amounts of nitrogen, phosphorous and sodium was studied in a pot experiment. Compared with control and diammonium phosphate treatments, the application of Na compound fertiliser increased plant height by 30% and 12%, leaf area by 97% and 40%, leaf relative organic weight by 10% and 7%, dry weight by 57% and 38%, water content by 347% and 55%, net photosynthetic rate (P_n) by 145% and 24%, primary light energy conversion of PSⅡ by 6% and 4%, photosynthetic electron transport rate by 16% and 8%, quantum yield by 14% and 5%, but decreased leaf malondialdehyde concentration by 58% and 18%, and penetrability of membranes by 50% and 26% respectively under drought stress. Meanwhile, the application of Na compound fertilizer significantly increased water use efficiency by 4%, compared with control pots. These results suggested that Na compound fertilizer could promote growth and enhance drought tolerance of Z. xanthoxylum, and the effectiveness was greater than diammonium phosphate.