At low levels, enterohemorrhagic Escherichia coli should be selectively isolated by suppressing competing microflora in meat samples. In conventional methods, MacConkey II Agar with C-T Sorbitol (cefixime-tellurite, CT-SMAC) which utilizes the ability of E. coli O157 to ferment sorbitol, and media containing E.coli -specific chromogenic substrates, are used for detecting E. coli O157. In this study, we compared two types of BD CHROMagar^TM O157 for the isolation of enterohemorrhagic E. coli O157 (improved BD CHROMagar^TM O157 and conventional BD CHROMagar^TM O157) with CT-SMAC by using the Miles-Misra method and evaluating the recovers from ground beef and human fecal samples. The results obtained are described below: 1. In the inoculation test with three media by the Miles-Misra method, improved BD CHROMagar^TM O157 inhibited the growth of all organisms except E. coli O157 better than the two other media and allowed easy differentiation from E. hermannii , which could not be distinguished on CT-SMAC. 2. In the E. coli O157 detection test for ground beef artificially inoculated with E. coli O157 at 1 cfu/g, the detection rate of improved BD CHROMagar ^TM O157 was 95%, CTSMAC 75% and conventional BD CHROMagar^TM O157 40%, respectively. 4. In the E. coli O157 detection test for E. coli O157 positive human fecal samples, the detection rate of improved BD CHROMagar^TM O157 was 54.5%, CT-SMAC 50% and conventional BD CHROMagar^TM O157 22.7%, respectively.