死亡率是用来衡量一部分人口中，一定规模的人口大小、每单位时间的死亡数目（整体或归因于指定因素）。死亡率通常以每年每一千人为单位来表示；因此在死亡率为9.5的10万人口中，表示这一人口中每年死去950人。死亡率有别于发病率，发病率是指一定规模的人口在一定时间内罹患该病添加加例数（发病率）。患病率是指一定时间一定规模人群中某病新旧病例总和。

辨别：

死亡率=当区当年死亡人数*1000/当区当年年中人口数‰。

死亡率可以得知一个地区的卫生习惯和医疗品质。通常越先进的国家死亡率越低，越落后的国家死亡率越高。

Mortality rate, or death rate, is a measure of the number of deaths (in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time. Mortality rate is typically expressed in units of deaths per 1,000 individuals per year; thus, a mortality rate of 9.5 (out of 1,000) in a population of 1,000 would mean 9.5 deaths per year in that entire population, or 0.95% out of the total. It is distinct from "morbidity", a term used to refer to either the prevalence or incidence of a disease, and also from the incidence rate (the number of newly appearing cases of the disease per unit of time).