Two new grayanane diterpenoid glucosides, rhodomosides A (1), B (2) and two new phenolic glycosides 3, 4 together with a known glucosyringic acid (5) were isolated from the roots of Rhododendron molle G. Don (Ericaceae). Their structures were elucidated on the basis of spectral analysis. Compounds 3, 4 and 5 were found to inhibit the proliferation of murine B lymphocytes in vitro, while compound 3 also showed stimulatory activity on the proliferation of murine T lymphocytes in vitro.