Haemagglutinin of vesicular stomatitis virus, Indiana serotype, was propagated in BHK21/13S cells, using diluted seed virus and multicyclic growth. In a 15 to 45 per cent sucrose gradient two haemagglutinins with different sedimenting properties could be separated. The proportions of these haemagglutinins depended on the input multiplicity of infection. In preparations obtained with undiluted seed virus, the proportions of the more slowly sedimenting haemagglutinin was strongly increased. The infectivity was associated with the lower band. In electron microscopy virions were found in the lower band whereas the upper band consisted of so‐called T particles and some rosettes. The two haemagglutinating components could also be separated by their densities in a CsCl gradient. The densities were 1.22 g/cm3for the virion‐containing band and 1.18 g/cm3for the upper band. The two haemagglutinating components had the same protein composition in acrylamide gel electrophoresis. The results obtained suggest that, in addition to the virion, the shorter T particles also possess haemagglutinating capac