Accidents are always the most important problem related to the safety of people. In this study, we attempt to explore the trend of the effects of accidents in terms of years of potential life lost and economic loss in the past 25 years. The Lee-Carter Model is used for exploring the trend of death rate. The time-varying mortality index from the Lee-Carter model is fitted by a time series model and nonlinear model to predict future accident mortality rate. The years of potential life lost is calculated based on information about life expectancy, and the Human Capital Method is used to figure out the economic loss caused by accidents. Finally, a time series ARIMA model is applied to predict the economic loss caused by accidents. The results show that accident mortality rate has trended upward, then downward in the past 25 years; it peaked at 70.04 deaths per 100,000 population in 1989, then declined after 1989 (1999 and 2009 are excluded due to the extraordinary events of the 921 earthquake and Morak typhoon). In addition, a time series model and nonlinear model are used for fitting a time-varying mortality index k(t), providing good results for predicting accident mortality rates from 2010 to 2011. Using the population of Taiwan in 2000 as a standard, the years of potential life lost per 1,000 population caused by accidents were 31.13, 21.44, and 10.06 in 1989, 1999, and 2009 respectively; the years of working life lost per 1,000 population were 29.56, 17.55, and 7.34 in those same years. The economic loss caused by accidents after adjusting for 2009 CPI peaked at 490.37 billion NT dollars in 1993, then began falling after 1999's 410.15 billion NT dollars, reaching 165.79 billion NT dollars in 2009. From 1985 to 2009, the economic losses caused by accidents declined 37.52%. In addition, the predictions of time series models show that, due to accidents, the years of potential life lost per 1,000 population were 8.86, 8.05, and 7.23; the working life years lost per 1,000 were 6.32, 5.52, and 4.72; and the economic losses were 147.55, 127.89, and 108.23 billion NT dollars from 2010 to 2012 respectively.