This study was conducted in Khorasan-Razavi during 23 months (since February 2004 to December 2005). The samples (83 samples) of suspected farms were collected from tongue and mouth epithelium and tested by indirect sandwich ELISA and RT-PCR. During the study, twelve foci during the year 2004 and 23 foci during the year 2005 (up to December) were approved. Maximum distribution of FMD foci was observed in spring (63%). Pearson's correlation coefficient and Chi-square tests were carried out for data analysis. Attention was paid to frequent traffic of farm in springs since there is an increase of the disease in this season . There was no correlation between the sheep density and the disease must be account in cattle . However , with respect to considerable sheep population in Iran and its role in persistence of the virus, the vaccination of sheep seems to be essential for the control of FMD.