The resent application and progress of non- quenched and tempered steel is reviewed. The mechanism of strength and toughness and the method to improve them are discussed. Some new research processes are presented，which include strengthening equation，solid solubility product equation of micro alloying elements，strengthening by intragranular ferrite （IGF），controlled rolling and cooling technology of non-quenched and tempered steel. The typical applications of various non-quenched and tempered steels in automotive industry are 1isted. The problems for the production and application of non-quenched and tempered steel in China are also analyzed. Some suggestions for enlarging future manufacture and applications in automotive industry are also put forward.