Three new pyrrolizidine alkaloids, verticillatins A (1), B (2), and C (3), together with seven known pyrrolizidine alkaloids (4-10), were isolated from the roots of Paris verticillata (Liliaceae). Their structures were determined by spectroscopic data and chemical evidences. Verticillatin A (1), verticillatin B (2), verticillatin C (3), heliovinine N-oxide (4), and indicine N-oxide (5) showed cytotoxicity against the HCT15 cell line, with IC(50) values of 67.6, 92.4, 35.7, 36.2, and 74.7 mu M, respectively.