The properties of bacterial cells agglutinated by phytohemagglutinins were compared. The growth of agglutinated cells was slightly delayed than that of normal cells. In the case of the binding of soybean agglutinin (SBA) to E. coli NIHJ, the morphorogical change of the cells was observed within 24 hr. The drug sensitivity of St. epidermidis s-3090 cells bound to SBA or Ricinus communis agglutinin was accerelated, whereas the sensitivity of cells bound to concanavalin A was decreased.