Melodinus cochinchinensis (Lour.) Merr. has been used in Traditional Chinese Medicine for the management of various ailments, yet its chemical constituents are rarely studied. This study was aimed to isolate terpenoid indole alkaloids (TIAs) from the aerial parts of M. cochinchinensis by the guidance of ultrahigh-performance liquid chromatography coupled with a tandem mass spectrometry (UHPLC-MS/MS), and to elucidate their cytotoxic, immunosuppressive and anti-inflammatory activities. Eight new TIAs (1 and 5-11) along with 21 previously described analogues were isolated with the basis of molecular networking developed by our previously reported TIAs from the species of Melodinus. The structures of new TIAs were elucidated by the analysis of extensive spectroscopic data. Among the tested isolates, 11-methoxytabersonine (25) exhibited considerable cytotoxic activity against human acute lymphoblastic leukemia (MOLT-4), breast adenocarcinoma (MCF-7), pro-myeloid leukemia (HL-60), lung adenocarcinoma (A-549), and hepatocelluar carcinoma (SMMC-7721) cell lines, which was more effective than the positive control, cisplatin. The 195-hydroxyvenalstonidine (21) displayed moderate immunosuppressive effect against Con A-induced splenocyte proliferation at 40 mu M, while 16,17-dehydro-19S-vindolinine (1) showed potent inhibitory activity on nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) expressions in LPS-induced RAW 264.7 macrophages.