This work was launched to study on the chemical constituents from Euphorbia thymifolia. Thirteen compounds were isolated from the 95% ethanol extract of the aerial parts of E. thymifolia by column chromatographies on silica gel, Sephadex LH-20, MCI, and ODS, and preparative HPLC, including two thymol derivatives(1-2), four alkaloids(3-6), five isocoumarins(7-11), together with two ellagic acids(12-13). All the compounds are listed as follows:(Z)-8,9-dehydro-9,10-diisobutyryloxythymol(1), 8-hydro-xy-9,10-diisobutyryloxythymol(2), N-(N-benzoyl-L-phenylalanyl)-L-phenylalanol(3), aurantiamide acetate(4), 1-carboethoxy-β-carboline(5), isoechinulin A(6), ethyl brevifolincarboxylate(7), euphorhirtin B(8), 4,5-didehydro chebulic acid triethyl ester(9), euphorhirtin G(10), pomegranatate(11), 3,3',4'-tri-O-methylellagic acid(12), 3,3'-di-O-methylellagic acid(13). Compound 1 is a new compound. Except for compound 4, the others were isolated from this plant for the first time. All the compounds were screened for anti-neuroinflammatory activity in vitro, and compounds 1-3 and 7 showed significant activity with IC_(50) values of 0.19,12.93,7.29,25.4 μmol·L~(-1).