It is generally recognized that some crops do not thrive when cropped annually on the same field, a phenomenon named "Iyachi" in Japanese, and phytotoxic compounds originating from crops are regarded as one of the causal agents. A typical example affected by continuous cropping is seen in Solanaceae plants such as eggplant (Solanum melongena L.). Therefore, we first attempted to survey phenolic compounds in the roots of eggplant. This paper deals with the isolation and structure elucidation of four phenolic amides, four phenolic compounds and an aromatic amine occurring in eggplant roots. The phenolic amides were identified as N-trans-feruloyl tyramine (V), N-trans-p-coumaroyl tyramine (VII), N-trans-feruloyl octopamine (VIII) and N-trans-p-coumaroyl octopamine (IX), among which V, VIII and IX are new compounds. The four phenolic compounds were identified as vanillin (I), isoscopoletin (II), ethyl caffeate (IV) and ferulic acid (VI), and the aromatic amine was identified as p-aminobenzaldehyde (III).