Abstract: It aimed to research the chemical constituents of Solidago canadensis Lour. A new sucrose derivative was isolated from the the methanol extract of Solidago canadensis Lour. with the technologies of silica gel, microporous resin, Rp-18, and Sephadex LH-20 column chromatography. It was identified as 2, 4, 6, 1′, 3′, 6′-O-hexaisovaleryl sucrose by 1D NMR, 2D NMR, high-resolution mass spectrometry, and acid hydrolysis method. Its mass spectrometry fragmentation behaviors were analyzed using high-resolution mass spectrometry and found that compound 1 was easy to break the glycosidic bond to produce the fragment at m/z 415. The ion at m/z 415 continued to eliminate the isovaleryl group as neutral or non-neutral form to generate a series of daughter ions. Compound 1 could inhibit NO production on LPS-induced neuroinflammatory responses in BV2 microglial cells at the concentrations of 5, 10, and 20 μmol·L^-1 to exhibit neuroprotective effect. Its half maximal inhibition rate of NO was measured to be 13.96 ± 0.78 μmol·L^-1.