A long-term-organ-culture is conducted with difficulty even today when cell culture techniques progress. For example, ex vivo mouse embryonic hearts preserving functional response are maintained for a short term (Dyer and Patterson, 2013). In contrast, embryonic hearts of the Japanese newt enable to be maintained in the culture medium for a long term (Taguchi et al.,1989). In the present study, amphibian hearts were organ-cultured using MEM etc. containing fetal bovine serum. After culture initiation, declined cardiac pulsation of sinus venosus including pacemaker cells within a few days, and morphological change were caused. Recently, the morphological and dysfunctional change occurred in cultured anuran hearts were improved by a new culture medium. I facilitate the study regarding functional changes of anuran hearts to various chemicals using the new culture medium.