New minor benzo[c]phenanthridine-type alkaloids, 12-hydroxycorynoline (I), C₂₁H₂₁O₆N, mp 245—246.5°, [α]D 0°, and 11-epicorynoline (IX), C₂₁H₂₁O₅N, mp 195.5—196.5°, [α] po°, along with 6-oxocorynoline (X), were isolated from Corydalis incisa PERS. (Papaveraceae). These structures were established by the spectroscopic studies and chemical correlations with the derivatives of corynoline. We have previously3) isolated from Corydalis incisa PERS. (Papaveraceae) four benzo[c]phenanthridine-type alkaloids, acetylcorynoline, acetylisocorynoline, corynoline and isocorynoline, along with fourteen alkaloids of other types. Further investigations on the alkaloids of this plant have led to the isolation of new minor benzo[c]phenanthridine-type alkaloids, 12-hydroxycorynoline and 11-epicorynoline, together with 6-oxocorynoline. This paper concerns the structures of these alkaloids.