Swine vesicular disease (SVD) and hog cholera (HQ viruses were eipthtl with ammonium sulfate or polyethylene glycd (PEG, MW 6,(X0) at 4t .SVD virus fluid txeatlwith8% (wN)ofPEGat4t for3 hours was foundthekestconcentxationfor thpitation, The retovery rate almcst reached to 1(0%. However, at the same unmarY condition but treated for 18 hours, the recovery rate of SVD virus was pxx, only 5.6%. 8% of PEG was also found excellent concentration for pathwion of HCV at 4t either for 3 or 18 hours rericd. Amznonium sulfate was found poor for the ecipitution of SVD and HC viruses,