<jats:title>Abstract</jats:title><jats:p>Together with five known sesquiterpenes, EtOH extraction of <jats:italic>Laurencia saitoi</jats:italic> yielded four new compounds, including three sesquiterpenes and one norsesquiterpene derivative. Their structures and relative configurations were elucidated by spectroscopic methods, including 1D‐ and 2D‐NMR (<jats:sup>1</jats:sup>H,<jats:sup>1</jats:sup>H‐COSY, HMQC, HMBC, and NOESY), as well as low‐ and high‐resolution mass‐spectrometric analyses.