<jats:title>Abstract</jats:title><jats:p>Three new stephaoxocane‐type alkaloids, stephalonganines A–C (<jats:bold>1</jats:bold>–<jats:bold>3</jats:bold>), together with the known eletefine (<jats:bold>4</jats:bold>), were isolated from the whole plant of <jats:italic>Stephania longa.</jats:italic> Their structures were fully characterized spectroscopically, and the absolute configurations of the new alkaloids were assigned by comparison of their circular‐dichroism (CD) data with those of 1,2‐dihydrostephaoxocanine (<jats:bold>5</jats:bold>), in combination with 2D‐NMR experiments.