The new steroidal alkaloid sevedinine was isolated from the aerial part of Korolkovia severtzovii. The structure of sevedinine was established as 6beta,12alpha-dihydroxy-5alpha-cevanin-3-one using spectral data, chemical transformations, and an x-ray structure analysis. The location of the tertiary hydroxyl in ten cevine alkaloids from Korolkovia severtzovii was corrected based on the results.