Abstract: Epilobium hirsutum L., as Onagraceae Miao medicine, and adulterants of Oenothera rosea L. are perennial herbs of different generas in the same family, with similar morphological characteristics, but different therapeutic effects, which were easy to confuse the two in clinical use, thus affecting the curative effect. In this study, the original plant identification, character identification and microstructure characteristics identification of Epilobium hirsutum L. and Oenothera rosea L. were carried out. Three different TLC development systems were determined, and the key parameters were optimized and verified. The results showed that there were differences in the original plant, characters and microscopic aspects between Epilobium hirsutum L. and Oenothera rosea L.. In the TLC of three unfolded systems, the chromatography-tested products of both were compared with kaempferol and quercetin. The spectra showed the same color feature spots at corresponding positions, and the Rf values were consistent with the standard. The study showed that the identification of crude drugs could effectively distinguish Epilobium hirsutum L. from Oenothera rosea L..