OBJECTIVE To study the quality standard of the ethnic medicine Diplazium lanceum， and to provide reference for its quality control.METHODS The medicinal material of D. lanceum was identified by properties， microscopy， and thin-layer chromatography（TLC）， and its moisture， ash， and extract contents were determined. The contents of chlorogenic acid and rutin in 10 batches of D. lanceum were determined by high-performance liquid chromatography . RESULTS The rhizome of D. lanceum is slender and creeping， the leaf is leathery and shriveled， and yellow sporangia are borne on the abaxial surface of the leaf. The transverse section of the leaf shows inclusions， sclerenchyma， phloem cells， etc.； the transverse section of the petiole shows ground tissue， sclerenchyma， endodermis， etc.； the transverse section of the rhizome shows ground tissue， tracheids， vascular bundles， etc.； and the powder shows spiral vessels and brown inclusions. The TLC identification results showed that the chromatogram of the test sample exhibited spots of the same color at the corresponding positions as the chromatogram of the chlorogenic acid reference substance. The content ranges of moisture， total ash， acid-insoluble ash， extract， chlorogenic acid， and rutin in the 10 batches of samples were 10.18%-12.43%， 7.08%-19.12%， 0.95%-10.62%， 14.13%-26.05%， 0.113 1-1.015 9 mg/g， and 0.009 9-0.208 9 mg/g， respectively. CONCLUSIONS In the quality standard of D. lanceum， the moisture content should be ≤12.5%， total ash content should be ≤20.0%， acid-insoluble ash content should be ≤11.0%， extract content should be ≥14.0%， and chlorogenic acid content should be ≥0.11 mg/g. The established method is simple， specific， and reproducible， and can provide a scientific basis for the quality control of D. lanceum.