The objective of this study is to calculate and compare the years of potential life lost (YPLLs) and cumulative mortality rates for 10 leading causes of death of Taiwan in 1979 and 1989. Mortality and population data abstracted from the national health statistis were used to calculate the YPLL, PYPLL (premature years of potential life lost), WYPLL (working years of potential life lost), VYPLL (valued years of potential life lost) and the CMR (cumulative mortality rates). The results showed that mortality from accidents has the highest YPLL's for all different calculations, and it has the highest cumulative mortality rate from age 7 to 59. The total less of wage due to accidents in 1989 was estimated to be NT$92 billion as compared with NT$83.4 billion which was the estimated sum of all other 9 leading causes of death. There was a general decline of cumulative mortality rates for major causes of death other than accidents, cancers and diabetes mellitus. Besides, the CMR of male were general higher than those of females. Before age 59, mortality due to accidents had the highest sex difference in CMR, which cancers and CVA showed the highest sex difference in CMR after age 59. We concluded that the mortality due to accidents had the most significant social impact in terms of economic loss, and there was no improvement during 1979 and 1989. We therefore recommend that more resource and attention need to be drawn on the research and prevention of accidents mortality.