Measles virus was propagated 3 successive times in three types of green monkey kidney-derived cells: Vero, E. 6 and CV-1. E. 6 cells proved to be most susceptible and gave the highest virus yields. The growth curve of measles virus showed the following features: * Infectivity titration for released and cell-associated virus fractions reached its peak at 90 hours P.I., where titers were 105.16 TCID50/ml and 105.66 TClD50/ml for released and cell-associated viruses respectively. * The haemagglutinalion test for released virus fractions showed negative results but cell-associated fractions started to give positive results at 90 hrs P. I. with a titer of 8 HA U, then it increased to a titer of 16 HAU at 114 hrs, finally it dropped to titer of 4 HAU at 138 hrs. P. L. * The development of complement fixing antigen started to become positive at 66 hrs P. I. for all associated fractions and the released virus fractions at 90 hrs P.I. * Dot-ELISA test had the ability to detect the virus antigens in the infected cells as early as 18 hrs P. I.