Abstract: In this paper, a new semantic and graphic model is introduced to analyze the present status of the natural gas industries and
markets in Japan and USA. The proposed method is based on the simulation of the physical flows and transaction flows of natural gas
(NG) by using MFM(Multilevel Flow Model) and GIS(Geographic Information System), and it is used for the inter-comparison of
supply, transportation, distribution and consumption situations of NG in Japan and USA. The obtained analysis results by the
proposed method suggest that mainly due to the geography factors, the transportation methods of NG in Japan are very complicated
to be compared with those of USA. This is the main reason why the natural gas downstream prices are so high in Japan. But recently,
the downstream prices in Japan are decreasing with the improvement of NG market efficiency through the introduction of deregulation
and the development of the energy saving techniques, while the upstream prices are increasing.