At the undergraduate level, there are only two majors under the first-level discipline of theoretical economics, namely economics and economic statistics, among which economics has no specific direction. The postgraduate stage will be subdivided into six majors: political economy, economic thought history, economic history, western economics, world economy, population resources and environmental economics. It can also be considered that the undergraduate economics major is the basic stage of political economics, economic thought history, economic history, western economics, world economy, population resources and environmental economics, or a comprehensive major of the above majors.
PS: As for the regional economics, international trade, finance and quantitative economics you listed, they are all applied economics majors.