Four new compounds, randainins A-D (1-4), were isolated from the leaves and twigs of Callicarpa randaiensis, which is an endemic species in Taiwan. Compounds 1 and 2 are diterpenoids with an unusual trans-7/5 ring system, whereas compounds 3 and 4 are diterpenoids possessing a trans-5/7 ring scaffold. The structures of the new compounds were established based on NMR and MS data analyses. Anti-inflammatory activities and cytotoxicity were tested and evaluated for these compounds. Compound 4 exhibited moderate inhibition of superoxide-anion generation with an IC50 value of 21.5 ± 2.5 μM.