Bioassay-guided fractionation of a petroleum ether extract of the roots of Stellera chamaejasme led to the isolation of seven new (stelleralides D-J, 1-7) and 12 known (8-19) daphnane diterpenoids. The structures and relative configurations of 1-7 were established on the basis of extensive spectroscopic analysis, including HRESIMS and comprehensive NMR techniques. All isolates were evaluated for anti-HIV activity in MT4 cells. All compounds tested, except 2, showed anti-HIV activity, and, especially, five 1α-alkyldaphnane diterpenoids (3, 4, 5, 10, and 11) exhibited extremely potent anti-HIV activity, with EC50 values of 0.06-1.1 nM and selectivity index values of more than 10,000.