The alkaloids in leaves of Nelumbo nucifera Gaertn.were isolated,identified and evaluated for their lipid-regulating activities on receptors 5-HT_2A and 5-HT_2C in this study.Eleven alkaloids were isolated and purified from lotus leaves by combining the traditional acid extraction and alkali precipitation method with modern high-performance liquid chromatography techniques,and were identified as pronuciferine N-oxide (1),pronuciferine (2),roemerine (3),noroxyhydrastinine (4),piperlonguminine (5),asimilobine (6),O-nornuciferine (7),N-nornuciferine (8),nuciferine (9),coclaurine (10) and armepavine (11),respectively.Among them,compounds 1,4 and 5 were obtained from the title plant for the first time.It is revealed that all alkaloids possessed interesting agonistic activities on 5-HT_2A receptor by an MTT assay on HEK 293 cell lines,which implied the potential chemical substance and pharmacological mechanism of the lipid-regulating activities of lotus leaves.