Chromium and its compounds are widely used in our economy. For example, stainless steel, refractory, plating, leather tanning, and dye are major industries using huge amount of chromium compounds. However, chromium compounds are toxic. It is necessary to understand the extent that chromium affects our health. The substance flow of Taiwan economy in 2002 is investigated in this study (Import 328845 ton; Export 171649 ton; Recycle 68 ton) and the framework of substance flow network is defined. The substance flows from economy to each environment media are estimated (Air 2012 metric ton; Water 942 metric ton; Soil 89015 metric ton), and the flow rate is taken into risk model (CalTOX). The result shows that there is a potential cancer risk of 7.6×10-6 and potential hazard quotient of 6.2. The bulk flow is further divided into several regional flows for calculating regional hazard on the basis of industry and economy activity density. Almost all administrative regions are suffering from over load of chromium, except Yilan, Hualien, Taidong, Nantou, Jiayi and Pingdong counties. It means that the industrial development is too dense in these regions.