[Objective]This study aims to investigate the mechanism of the interaction between ergosta-7,22E-dien-3β-ol, an active sterol of Poria, and progesterone receptor (PRGR) and the potential therapeutic effects via bioinformatics and molecular docking.[Method]The TCMSP database was used to screen the active ingredients of Poria, and MEGA X (10.0.5) was used for alignment of multiple PRGR sequences. The primary structure of PRGR was analyzed by ProtParam, and the hydrophobicity of PRGR was predicted by Protscale. The amino acid sequence of PRGR was analyzed by Prosite, and the secondary structure of PRGR was analyzed on NPS@SOPMA. The RCSB PDB database was used to predict the tertiary structure of PRGR via the homologous modeling method. DeepLoc-2.0 website was used to predict the subcellular localization of PRGR. SwissDock was employed to simulate the molecular docking between ergosta-7,22E-diene-3β-ol and its potential target PRGR (3O5Q).[Result]The PRGR protein consisted of 933 amino acid residues, with a relative molecular mass of 98 980 and a theoretical isoelectric point of 6.09, being a hydrophilic unstable protein. Its secondary structure was dominated by random coils (70.31% of the total), and this protein contained nuclear receptor ligand-binding domains (NR LBDs) and C4-type zinc-finger structure, which suggested its core function in nuclear signaling. Ergosta-7,22E-dien-3β-ol was anchored to the PRGR ligand-binding pocket through hydrophobic interactions and hydrogen bonding, and the key binding sites involved residues such as Leu and Ala. PRGR was highly conserved in primates, with branching values of more than 98% in the species (chimpanzee and bonobo) with closest affinity to humans. PRGR may be involved in the immune regulation through the nucleus and the outer membrane of mitochondria. Molecular docking revealed that ergosta-7,22E-dien-3β-ol may form a stable complex with PRGR.[Conclusion]This study elucidates the molecular binding mechanism of a sterol in Poria with PRGR, providing theoretical support for the development of immunomodulatory drugs targeting PRGR and the precise utilization of resources with both medicinal and edible values. Meanwhile, this study provides new ideas for the research on natural product-nuclear receptor interactions.