Phytoene desaturase (PDS) is the upstream key enzyme of carotenoid metabolic process of Dunaliella bardawil. According to the mRNA that NCBI published before (GenBank: Y14807), the PDS coding region was obtained through genome walking and nesting PCR. Due to that 325 bp in 5’ coding region were not matched with the mRNA published before., 5’ RACE was used to validate the 5’ sequences and the final result of 5’ RACE was matched with the 5’ sequences isolated. The sequence of promotor and terminator were also obtained by genome walking. The full length of PDS gene isolated included 8113 bp coding region (From ATG to TAA), 3010 bp upstream sequence of coding region and 1555 downstream sequence. 12 Exons and 11 introns were found in the cDNA ORF and coding region. Several kinds of transcription factor binding sites were predicted in the promotor of PDS by bioinformatic software.