Two new alkaloids, named 1,1-dimethyl-6-methoxy-7-hydroxyl-1,2,3,4-tetrahydroisoquinoline (1) and (1R)-(4-hydroxybenzyl)-7-hydroxyl-8-O-beta-d-glucopyranosyl-1,2,3,4-tetrahydroisoquinoline (2), together with 11 known compounds (3-13), were isolated from the tubers of Corydalis humosa. Their structures were elucidated on the basis of their spectroscopic and chemical evidence.