Evodiae Fructus (the dried, unripe fruit of Evodia rutaecarpa Hooker f. et Thomas (Rutaceae)) is an herbal drug recommended for the treatment of abdominal pain, nausea, diarrhea, hernia, and dysmenorrhea in Chinese medicine. Previous studies suggest that the pharmacological actions of E. rutaecarpa fruit on cardiovascular, gastrointestinal, or central nervous systems may be due to the effect on the adrenergic, muscarinic, histamine, or 5-hydroxytryptamine (5-HT) receptors or the L-type Ca2+ channel. This study was conducted to evaluate whether E. rutaecarpa fruit extract can interact with these receptors or binding sites by radioligand receptor binding assays and to isolate the responsible principles. Two active principles, 5-methoxy-N,N-dimethyltryptamine (1) and N,N-dimethyltryptamine (2), were isolated from the dried, unripe fruit of E. rutaecarpa. They interacted with 5-HT1A receptors with Ki values of 28 nM and 0.41 µM, respectively. Compound 2 was found in the E. rutaecarpa fruit and the genus Evodia for the first time.