1874 O. Tseidler, a German chemistry doctoral student, described the synthesis of dichlorodiphenyltrichloroethane in his paper, but did not talk about its insecticidal effect. Later, this compound was also called 223 for short. Because two is di and three is tri in English, it is also called DDT. We are transliterated from DDT, and we have a little image when spraying. More than 60 years later, Miller (P.H.Müller, 1899 ~ 1965), a chemist of J.R.Geigy Company in Basel, Switzerland, made it again and found its insecticidal effect. 1942, the company started mass production. 1944, a large-scale typhus occurred in Naples, Italy. After a few days of extensive spraying DDT, typhus was controlled. 1945 aerial photography in the south Pacific killed mosquitoes, and local malaria was controlled. According to FAO statistics, from 1948 to 1970, 50 million people were saved from malaria due to the use of DDT to kill mosquitoes. DDT is widely used to kill leaf roller moth, red bollworm, mosquito, fly, bug, cockroach and so on. Miller therefore won the 1948 Nobel Prize in Physiology and Medicine.