Background and Aims: Foot and Mouth Disease is one of the important live stocks contagious viral diseases caused by Aphtovirus genus, belonging to the family of Picornaviride. The important characteristic of FMD virus is high mutation that gives rise to diversity of antigen on the surface of neutralizing proteins. For this reason FMD virus has 7 distinct serotype and many subtypes. Vaccination is one of the methods to control the disease caused by different type and subtype of FMD virus, the effective vaccine should have virus with close relationship with field virus and also many passage on cell culture may cause mutation on viral genome. The rate of genetic changes of FMD virus type O2016 during of 70 passages in BHK monolayer cell is the main reason of this paper. 
Materials and Methods: After determining the type of virus in epithelium sample by ELISA, the virus inoculated in BHK monolayer cell for 70 consequence passage. Harvested viruses in 10 selected passage (P1,P10 , P20,P30,P40,P50,P60,P70) were subjected to RT-PCR, ELISA, titration, real time PCR, Double dimension virus neutralization test for  immunological relationship value (r value) and Nucleotide sequencing of 1D segment of viral genome.
Results: Harvested FMD virus type O2016 from passage 1 until 70 were constant. No significant change was detected neither in sequencing nor in r values.
Conclusions: The virus has displayed very little change over the course of repeated passages, which can even be claimed to stay unchanged.