The culture conditions for the intestinal protozoa of the termite were examined. Some flagellate survived in the conditioned medium for long period. In the conditioned medium filtrated or centrifuged, these protozoa did not survive for long time. When the isolated bacteria were added into the treated media, the survival rate of flagellates was recovered. Some bacteria may play a role of the conditioning of the medium. It is suggested that the environment of the hindgut is controlled by the intestinal bacteria.