Twinty commonly used commez-Lca’l, disinfecto.nts (disinfeo- tnts, nntiseptics, sanitizers and detergents) were evaluatedfor their virucidal activity against two viruses the Poliovirus type 1 ar.the Vaccinia-virus~ Many trials were assayed to pro-duce a suitable antigen. We found that the adventitious protein in antigen within the limite of 10 mg ./ml had no influence on .the virucidal activity of both betadine and formaline; As well6 loglOI.D/m1~ virus titer was found to be sufficient if virus”;virucide mixture was completely separated his work is a trail to take a step forward as regardsthe development of a standard technique for the ~aluation ofthe effectiveness of virucidea . After a. contact period between’.virus and virucide the mixture was filtered through a gelcolumn. to separate the virus completely from the virucide aco- rding to their molecular dimensions. The tested disinfectants were diluted as recommended by the manufacturers.The virucidal efficienoy of the virucides was judged bythe time required toinactivate 4 loglO I.D./ml. virus/ml.virucide.