Two new carbazole alkaloids (1,2) and six known carbazole alkaloids (3-8) were isolated from Clausena anisum-olens. Their structures were elucidated based on extensive spectroscopic analysis. All isolated compounds (1-8) were evaluated for their anti-HIV effects on virus replication in MT-4 lymphocytes infected by HIV-1(NL4-3) Nanoluc-sec virus, and new carbazole alkaloid 1 exhibited anti-HIV activity with an EC(50) value of 2.4 mug/mL and SI of 7.1.