The main difference between the two was the evaluation criteria. The source journal of the CSSSCI was the foundation of the CSSSCI evaluation system and one of the most important journals in the CSSSCI evaluation system. The source journals were selected according to the evaluation criteria of the CSSSCI. These journals met the requirements of the CSSSCI evaluation in terms of content, style, and structure. Therefore, the source journals of the SSSCI were an important part of the SSSCI evaluation system and an important basis for the SSSCI evaluation organization. The extended version was a further expansion of the source journals of the SSSCI, adding some new evaluation criteria to include many emerging journals and fields. The expanded version of the journal covered a wider range of content. More journals were recognized as the source journals of the SSSCI, and more evaluation indicators and methods were provided. Therefore, the main difference between the source journal and the extended version of the journal was the evaluation criteria. The source journals were selected according to the evaluation criteria of the CSSSCI, which was an important part of the CSSSCI evaluation system. The extended version added some new evaluation criteria to cover a wider range of content, and more new journals were recognized as CSSSCI source journals.