Evodiae Fructus (the dried, unripe fruit of Evodia rutaecarpa) is an herbal drug used in Chinese medicine for abdominal pain, nausea, diarrhea, hernia, and dysmenorrhea. Previous studies suggest its pharmacological actions on cardiovascular, gastrointestinal, or central nervous systems may involve adrenergic, muscarinic, histamine, 5-HT receptors, or L-type Ca2+ channels. To explain these actions at the receptor level, this study evaluated whether E. rutaecarpa fruit extract interacts with receptors via radioligand receptor binding assays and isolated the active principles. 5-Methoxy-N,N-dimethyltryptamine (1) and N,N-dimethyltryptamine (2) were isolated from the dried, unripe fruit. They interacted with 5-HT1A receptors with Ki values of 28 nM and 0.41 µM, respectively. Compound 2 was found in E. rutaecarpa fruit and the genus Evodia for the first time. The ethanol-water (1:1) extract of E. rutaecarpa fruit interacted with 5-HT1A receptors (Ki = 18.4 µg dry weight/mL) and other receptors. The EtOH extract (Ki = 1.64 µg extract weight/mL) was separated into H2O-soluble and insoluble fractions, with the former showing significant interaction with 5-HT1A receptors. Further separation of the H2O-soluble fraction yielded compounds 1 and 2. Comparison with other compounds from E. rutaecarpa showed only dehydroevodiamine, synephrine, and rhetsinine had moderate interaction with 5-HT1A receptors (Ki > 30 µM), while evodiamine, rutaecarpine, limonin, isorhamnetin 3-O-galactoside, and quercetin 3-O-galactoside had no significant interaction (Ki > 100 µM or >10-4 M).