Three new sesquiterpene pyridine alkaloids with a β-dihydroagarofuran sesquiterpene skeleton, celangulatin G(1), H(2) and I(3), and one known alkaloid 4 were isolated from the middle-polar extracts of the root bark of Celastrus angulatus by bioassay-guided separation. Their chemical structures were elucidated mainly by the analyses of the MS and NMR spectral data. Celangulatin G(1), H(2), I(3) and 4 showed KD50 against Mythimna separata were 849.61, 80.24, 96.29 and 50.98 µg g−1, respectively.