Abstract:MicroRNAs (miRNAs) are important gene regulating factor in plant. A series of researches show that expression of miR417 can be controlled by salt stress. In high salt conditions, miR417 of Arabidopsis has negatively regulating roles on the rate of the seed germination and seedling survival. According to the miRNA417 sequence analysis of known plants in miRbase database, the pre-miR417 has been successfully cloned from halophyte Halostachys caspica by the PCR technique in the present study. After the construction of plant expression vector pCAMBIA1301, the recombinant plasmid was transformed to Arabidopsis thaliana. The result indicated that the over-expression lines of HcmiR417 and miRNA417 had lower rates of seed germination and seedling survival than those of the wild type, but there was no significant difference between the two transformed lines. It primarily suggests that HcmiR417 plays a negative role in the seed germination and seedling survival, while the function of miRNA has no difference between Arabidopsis and H.caspica.