Some plant miRNAs are involved in gene expression regulation under salt stress.KcmiR398,a miRNA from halophytic Karelinia caspica,presented a significant differential expression under salt stress.In order to investigate the target genes of KcmiR398 and its regulatory effect to the target genes,we performed online bioinformatics analysis (http://plantgrn.noble.Org/psRNATarget/),and Cu/Zn superoxide dismutase (SOD) genes CSD1 and CSD2 were predicted as the target genes of KcmiR398.Full length sequences of CSD1 and CSD2 (named KcCSD1 and KcCSD2 respectively) were cloned by using RACE technology.qRT-PCR results showed that:(1)The expression of KcmiR398 was up-regulated in the stems of the salt-stressed K.caspica,but down-regulated in the new leaves;The expression of KcCSD1 was up-regulated in the old leaves of the salt stressed plant,but down-regulated in the old stems and roots;The expression of KcCSD2 was up-regulated in both old stems and roots of the stressed plant.(2)When plant stressed with 300 mmol/L NaCl for 24~48 h,the expression of KcmiR398 showed no significant difference compared to the control;the expression of KcCSD1 was more than 3-fold of that of control;whereas the expression of KcCSD2 showed no significant difference with salt treatment.These results indicated that the expression of KcmiR398,KcCSD1 and KcCSD2 were tissue differential,and the expression of KcmiR398,KcCSD1 and KcCSD2 was influenced by salt stress,which makes K.caspica resist to the damage of oxidation caused by salt stress.