Abstract: 【Objective】 To investigate the effect of exogenous ALA on chlorophyll synthesis in jujube seedlings under NaCl stress. 【Methods】 In this experiment jujube seedlings were used as experimental materials by hydroponic to study the content of endogenous ALA, porphobilinogen, protoporphyrin IX, Mg-protoporphyrin IX, protochlorophyll and chlorophyll of jujube seedlings under external spraying of ALA against NaCl. 【Results】 Compared with 150 mmol/L NaCl treatment, application of exogenous spraying of 100 m-g/L ALA significantly increased the endogenous ALA content, porphobilinogen content, protoporphyrin IX content, Mg - protoporphyrin IX content, and protoporphyrin content of jujube seedlings, which were increased by 44.8%, 20.8%, 21.2%, 26.4%, 36.5%, 36.0%, 38.4% and 41.2% respectively compared with NaCl treatment. This study also found that the conversion process of chlorophyll synthesis blocked the site in ALA →PBG. 【Conclusion】 Exogenous ALA can promote the chlorophyll synthesis of jujube seedlings under NaCl stress,thereby promoting the growth of jujube seedlings.