This article briefly introduced the current view of the U.S.National Standard Occupational Classification System,reviewed its history of development,rules and methods of revision,the characteristics and applications of the new Standard Occupational Classification system,and the endeavor in developing Occupational Information Network(O*NET).Lastly,based on the experience of the development of U.S.National Standard Occupational Classification System,the authors gave some suggestions on revising national occupational classifications in China,including collecting advices from all kinds of people in society,emphasizing scientific and formalized occupational classification criterion,collecting empirical information about jobs and occupations,taking effective measures to ensure the update of the national occupational classification system of China.