Abstract: Nostoc flagelliforme is a terrestrial nitrogen-fixing cyanobacterium with strong drought adaptability.We performed 2-DE analysis,gel image analysis and MALDI-TOF-TOF/MS to compare and identify differential proteins from N.flagelliforme subjected to desiccation.The results indicated that Ferritin,Dps family protein expression quantum gradually declined under desiccation stress.The Ferritin gene was cloned by designed degeneracy primer based on identified amino acid sequences.A full length of 540 bp DNA was obtained (GenBank access number: HM854287).Homology analysis showed that the N.flagelliforme Ferritin gene had high consensus regions.The secondary structures of Ferritin were made up of α helix and random coil.The RT-PCR showed that mRNA of Ferritin gradually declined under drought stress.The Ferritin gene was expressed in Escherichia coli,and a 22.4 kD heterologous protein was observed.The results laid a foundation for understanding the drought-resistant molecular mechanisms and protection mechanisms of N.flagelliforme in extreme arid environments.