Two new guaiane-type sesquiterpenoids (1 and 2) and one new eudesmane-type sesquiterpenoid (3) were isolated from Saussurea laniceps. The structures of these compounds were established by spectroscopic methods, and the absolute stereochemistry of compounds 1 and 2 was determined by Mosher's method. The immunomodulatory activities of compounds 1-3 were evaluated. Of these, compound 3 showed significant inhibition of the proliferation of murine T and B cells in vitro.