A study was made to determine suitable plate-in-bottle media for enumeration and isolation of the anaerobic faecal bacteria of mice. Comparison of non-selective media indicated that colony counts were higher on M-SM10, M10 and M-M98-5 than on EG, W & E medium and BHI, and those on M-SM10 were always the highest. Bacteroidaceae counts on M-SM10, M10, M-M98-5 were particularly high. On the other hand, in chloroform-treated faeces which contain only Clostridial spores, colony counts were higher on EG and W & E medium than on M-SM10, M10 and M-M98-5. These results indicate that suitable non-selective media vary according to the bacterial species to be enumerated and isolated.