Taq DNA polymerase with different concentrations of other thermostable DNA polymerases with 3' to 5' exonuclease activity (PFU and Vent) was used in the amplification of large fragments (2 Kb, 3 CD genes) of foot and mouth disease virus (FMDV). Such long-distance polymerase chain reaction (LD-PCR) was conducted to reduce mismatch extension rates and improve epidemiological cloning and sequencing Studies. When enzyme mixtures in the reaction were optimized. The best results were obtained with Tth and PFU polymerases at concentrations of 2.50-0.40, 2.50-0.50 and 2.50-0.60 units, respectively