Nine new epipoly(thiodioxopiperazine) (ETP) analogues, chetocochliodins A<b>-</b>I (<b>1</b>-<b>9</b>), along with two known ones, chetoseminudins E and C (<b>10</b> and <b>11</b>), were purified from the fungus <i>Chaetomium cochliodes</i>. The planar structures and absolute configurations of these new compounds were determined by extensive NMR spectroscopic analysis, CD spectra, and chemical reactions. Shielding effects from the indole on the 3-SCH<sub>3</sub>/3-OCH<sub>3</sub>/3-OCH<sub>2</sub>- groups facilitated the determination of relative configuration of the analogues. Compound <b>9</b> was cytotoxic, suggesting the importance of the sulfide bridge for the diketopiperazine bioactivities.