On case each of folie a trois and folie a deux was reported on. Case 1 consisted of a husband and wifw with paranoid type schizophrenia, and their daughter, who developed the disease in reaction to them. This husband and wife formed ”schizophrene Gemeinschaft”, and experienced delusions of persecution, delusions of reference and auditory hallucinationsof the same nature through which they involved their daughter. In Case 2, induced by her daughter with hebephenic type schizophrenia, a mother also developed delusions of persecution and auditory hallicinations of the same nature, in a reactive manner. In this case, the mother's belief in superstitution also posed a problem. It should be note that of the cases called folie a deux, there are some which come into being only under specific conditions between schizophrenics, as in Case 1, and can be understood as a schizophrenic community.