To investigate the chemical constituents of the ethyl acetate fractions in Justicia gendarussa Burm.f..The chemical constituents in ethyl acetate fractions of 95% ethanol extract from J. gendarussa were isolated and purified by repeated silica gel column chromatography,ODS open column,Sephadex LH-20 chromatography and semi-preparative HPLC.Based on HR-ESI-MS,NMR,X-ray single crystal diffraction and other spectral data,21 compounds were identified as 2,3,3a,5-tetrahydro-1H-benzo［d］pyrrolo［2,1-b］［1,3］oxazin-1-one (1),4′-hydroxyacetophenone (2),apocynin (3),baishouwu benzophenone (4),p-hydroxybenzaldehyde (5),salicylic acid (6),2,4-dihydroxyacetophenone (7),2,5-dihydroxyacetophenone (8),1,3,5-trimethoxybenzene (9),syringylethanone (10),nonanedioic acid (11),(+)-pinoresinol-O-β-D-glucopyranoside (12),corchoionoside C (13),patuletin-3-O-glucoside (14),commicarpiflavonol glucoside A (15),1,2,3-trimethoxy-5-nitrobenzene (16),4-nitrophenol (17),glyceryl monooleate (18),tetradecanoate (19),steraric acid (20),palmitatic acid (21).Compounds 1 and 16 were discovered from natural resources for the first time.All compounds were isolated from this plant for the first time and were screened for anti-inflammatory activities.The IC50 values of compounds 4,6 and 8 were lower than that of positive drug (quercetin as positive control,IC₅₀=16.94±0.40 μM),which indicated compounds 4,6 and 8 had significant anti-inflammatory activities.