Three new sesquiterpenes: 4-acrylic-6-methyl-α-tetralone (1), ainsliaea acid A (2) and ainsliaea acid B (3), together with 8 known compounds (4-11) were isolated from the whole herb of Ainsliaea glabra and their structures were established by means of 1D and 2D NMR spectroscopy and HR-ESIMS.