The fruit of Chinese jujube(Ziziphus jujuba)possesses extremely high concentrations of ascorbic acid(As A).The accumulation of As A,the expression patterns of the nine genes related to As A metabolism as well as the activities of five enzymes involved in As A synthesis,oxidation and recycling were investigated during fruit development in Z.jujuba Mill.‘Jinsixiaozao’.The results showed that the high level of As A accumulation in jujube fruit is due to a contribution from both As A biosynthesis and As A recycling.It is suggested that L-galactono-1,4-lactone dehydrogenase,ascorbate peroxidase and monodehydro-ascorbate reductase are the crucial genes/enzymes of jujube As A synthesis,oxidization and recycling,respectively.These results provide useful new insights into the regulatory mechanisms of As A accumulation in Chinese jujube. The accumulation of As A, the expression patterns of the nine genes related to As A metabolism as well as the activities of five enzymes involved in As (As A). The fruit of Chinese jujube (Ziziphus jujuba) possesses extremely high concentrations of ascorbic acid A synthesis, oxidation and recycling were investigated during fruit development in Z.jujuba Mill. ’Jinsixiaozao’.The results showed that the high level of As A accumulation in jujube fruit is due to a contribution from both As A biosynthesis and As A recycling. It is suggested that L-galactono-1,4-lactone dehydrogenase, ascorbate peroxidase and monodehydro-ascorbate reductase are the crucial genes / enzymes of jujube As A synthesis, oxidization and recycling, respectively. Sese results provide useful new insights into the regulatory mechanisms of As A accumulation in Chinese jujube.