ABSTRACT BACKGROUND: Apical Membrane antigen 1 (AMA-1) is an important membrane protein that presents in all Plasmodium species and participates in critical phases in the attraction of cells.  In human, it is one of the most immunodominant antigens with a protective immune response simulation role Apical Membrane antigen 1 (AMA-1) is an important membrane protein which presents in all Plasmodium species and is located on the surface of merozoite and sporozoites that participates in critical phases in attraction of human red blood cells by merozoites and hepatocytes by sporozoites, so in human, it is one of the most immunodominant antigens with a protective immune response simulation role. Since extra information is necessary to lighten of AMA-1 scope, we equaled genetic variation in P.vivax AMA-1 from 40 Iranian isolates with those reported from the other malarious countries.METHODS: Blood samples were collected from 40 patients’ positive of P.vivax, and genomic DNA was extracted from the blood. The nucleotide sequence for 446 amino acid (AA) residues (42–488 of PvAMA-1) of AMA-1 gene was amplified via PCR and then sequenced.RESULTS: A total of 24 different haplotypes were recognized between samples. No new haplotype was determined in this research that was reported previously in other regions of Iran and the world. We detected 37-point mutations at the nucleotide level in their sequences and showed 43 amino acid variations, at 37 positions in which 6 sites demonstrate trimorphic polymorphism, and the others were dimorphic.CONCLUSION: Sequence analysis of the major haplotype showed 95% similarity with P.vivax Sal-1 AMA-1 gene and high level of allelic diversity at the domain I of PvAMA-1 among P. vivax isolates of Iran. Because PvAMA-1 is noticeable as vaccine candidate antigen, these documents provide valuable information for the development of malaria vaccine.KEYWORDS: Plasmodium vivax, PvAMA-1, Iran, Genetic variation, Sistan