N-Benzyloxycarbonyl-L-alanine 4-hexadecanoyl-2-nitrophenyl ester can form thermoreversible hard gels at less than 1% by mass in methanol or cyclohexane; TEM (transmission electron micrograph) and SEM (scanning electron micrograph) of gels reveal rod-like fibres and huge aggregates with branched structure, which are mainly assembled by hydrogen bonding between N-H and C=O of the urethane bond.