Ciliates Epidinium ecaudatum f. fasciculus were isolated from the rumen of cow and cultured in vitro for about 12 months. The cultivation has begun from an inoculum comprising 16 cells of protozoa. Most favorable conditions for a long term survival of ciliates were observed when the salt solution based on NaCl, KH2P04 and NaHC03 was used to culture of protozoa and C02 to produce the anaerobic conditions. It was observed that cultured ciliates readily engulfed and digested starch grains. Contrary to that neither hay nor cellulose particles were ingested. Hay was, however, the necessary component of the medium to keep the protozoa alive for a long period. Soluble carbohydrates such as xylose, glucose, fructose, sucrose and trehalose negatively influenced the growth of ciliates and most detrimental were xylose and trehalose. The influnce of the other ciliates on the survival of Epidinia was also tested. An establishment of Entodinium caudatum resulted in the disappearance of Epidinium ecaudatum fasciculus, while Anoplodinium denticulatum had no effect. On the other hand Diploplastron affine died in the presence of Epidinium ecaudatum f. fasciculus. It is possible that some ecological relationships between the cocultured species of ciliates have to be considered to explain the observed phenomena. This study was supported by EU infrastructure grant QLRI-CT-2000-01455.