Two new rare benzyl-aporphine alkaloids, thaliculine (1) and 6a,7-dehydrothaliculine (2), were isolated from the roots of Thalictrum cultratum Wall. Their structures were determined based on spectroscopic analysis including 1D, 2D NMR, and HR-ESI-MS. The stereochemistry of 1 was assigned by ECD spectroscopy. Compound 1 exhibited weak cytotoxicity against HL-60 cell line with IC50 value of 31.40 mu M.