We have examined the antigen specificity in orally tolerant mice fed with the casein(CN) diet. In contrast to previous reported results of studies on oral tolerance, these mice responded poorly to ovalbumin(OVA) and ovomucoid(OM), as well as $alpha$sl-enriched fraction of these cells suppressed anti $alpha$sl-CN antibody production of naive mice, but could not significantly suppressed antibody response of previously immunized recipient mice. These results indicate that oral tolerance was not medicate through suppressor T cell activities.