Abstract: When the natural radioactivity was discovered at the end of 19th century, especially after Radium was extracted, the radioisotopes were put into practice quickly. But due to the restriction of manufacture ability, it developed very slowly. After 1950s, with the improvement of manufacture ability, the radioisotopes developed rapidly, being widely used in many fields such as nuclear instrument, irradiation processing, cancer treatment, irradiation breeding, etc. In 21th century, owe to the progress on isotope analysis & measurement technology, biology technology and semiconductor technology, the isotope application has been making great achievements again in the aspects of isotopic tracing, stable isotope technology and nuclear medicine, etc. As a traditional subject, isotope technology has been blooming with powerful vitality and broad prospect. This paper mainly introduced the application and development of isotopes in the fields of industry, agriculture, medical treatment, environment and science research, including the most recent achievements on isotope application.