The burden of road traffic injuries in the People's Republic of China is increasing as evidenced by trends since 1951. Data from the National Statistical Office, Ministry of Communications and the Traffic Administration Bureau were analyzed. Absolute numbers of crashes, fatalities, and injuries, as well as fatalities per 100,000 population and motorization (number of vehicles per 1000 population) were used as indices to measure trends. Regional variations in trends and the characteristics of people injured or killed were also analyzed. Road traffic crashes increased 68-fold, from around 6000 in 1951 to 413,000 in 1999. Excessive speed was the main reported cause of the crashes. The injuries increased 56-fold--from around 5000 to 286,000--and fatalities 97-fold--from 852 to around 84,000--over the same period. The crash, fatality and injury rates also increased after 1985, due to increased motorization spurred by rapid economic growth. The number of four-wheel motor vehicles increased from 60,000 in 1951 to just under a million four-wheel motor vehicles in 1975 and to 10 million in 1987. The number of four-wheel motor vehicles then rose to 50 million in 1999, with an additional 30 million motorcycles. The increase in motorization and fatalities affected all the provinces. Road traffic injuries are the leading cause of death for populations up to the age of 45 years and the leading cause of working-life years lost in China.