Abstract: The Carbazole alkaloids from Murraya tetramera Huang and their cytotoxic activities were investigated in this study.The ethanol extract from Murraya tetramera Huang were separated by chromatographic techniques.The structures of these compounds were identified by ¹H NMR,¹³C NMR,HSQC,HMBC.they were β-sitosterol (1),1-methyl-3-propionylcarbazole (2),1-methoxy-3-ethylCarbazole (3),1-methoxy-3-formylcarbazole (4),1-methoxy-3-methylcarbazole (5),1-carboxymethylester-3-methylcarbazole (6),1-carboxymethylester-3-ethylcar-bazole (7),manembine (8).All of these compounds were isolated from this plant for the first time except compound (1).The IC₅₀ of compound 2,3,4,5,and 7 against SMMC-7721 was 40.93 ± 0.66,46.03 ± 2.05,114.21 ± 5.67,15.79 ± 0.99 and 185.1 ± 0.44,respectively.The compound (2),(3),(4),(5),(7),showed good cytotoxic activities against SMMC-7721.

Key words: Murraya tetramera Huang, folk medicine, carbazole alkaloids, cytotoxic activity, NMR