Enzymatical dispersion method was applied to primary cell culture system from middle-ear epithelium of the guinea pig. Collagen gel and fibronectin coated Thermanox cover slips were used as culture substrates, and both materials could keep the types and morphological characteristics of the cultured cells. Enzymatic activities of succinate dehydrogenase and adenosine triphosphatase in mitochondria were also examined. And strong activity of succinate dehydrogenase was especially revealed in the ciliated cells and protuberant type of the non-ciliated cells.