Pogocablanols A–G (1–7), seven new compounds with an unprecedented sesquiterpenoid skeleton, were isolated from the aerial parts of Pogostemon cablin. This novel type of sesquiterpenoids, named pogocablane-type sesquiterpenoids, possesses a bicyclic nonisoprenoid system, including a five-membered carbocycle with a methyl group, a six-membered carbocycle with two methyl groups, and a methylene connecting the two carbocycles. Particularly, three isomers have an interesting 1-oxaspiro[4,4]nonane moiety. Their structures and absolute configurations were determined using extensive spectroscopic evidence, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Pogocablanols A–D (1–4) exhibited a concentration-dependent inhibitory effect on rat jejunum smooth muscle contraction induced by acetylcholine, with Emax values varying from 48.87 ± 4.01% to 69.02 ± 7.54%. Preliminary structure–activity relationship analysis suggested that the oxaspirocycle and the pyran ring in pogocablanols are important structural features for the relaxing effects on jejunum smooth muscle.