The key research base of humanities and social sciences of Sichuan Provincial Department of Education belongs to the provincial research base level. As far as I know, research bases in China can be divided into three levels: national, provincial and municipal. National research bases are usually led and funded by the central government or the national education department. Provincial research bases are established and managed by provincial governments or provincial education departments. The municipal research base is responsible for the municipal government or the municipal education department. According to the information mentioned in the question, the key research base of humanities and social sciences of Sichuan Provincial Department of Education belongs to the provincial research base.