Daphne genkwa (Thymelaeaceae) has been used as a folk medicine in China. We investigated the effects of D. genkwa and Jyu-So-To on various pharmacologic models in mice including the azoxymethane (AOM)-induced colonic aberrant crypt focus formation assay, ornithine decarboxylase (ODC) activity assay, and two types of mouse ear swelling model. Administration of 236.3 ppm of Jyu-So-To in drinking water significantly suppressed AOM-induced colonic aberrant crypt focus formation (p < 0.05), with an inhibitory ratio of 46.7%. The effects of several extracts with organic solvents of D. genkwa on murine epidermal ODC activity were examined. In particular, the inhibitory ratio of the n-hexane extract was 30.8%. In the 12-O-Tetradecanoylphorbol-13-acetate (TPA)-induced ear edema model in mice, the methanol extract resulted in 56.3% inhibition compared with the control. On the other hand, there are two peaks of responses at 1 h (immediate-phase reaction; IPR) and 24 h (late-phase reaction) in biphasic cutaneous reactions, which are enhanced in the dinitrofluorobenzene model (DNFB). The water extract of D. genkwa clearly inhibited the IPR ear swelling. These results suggest that D. genkwa and Jyu-So-To should be a promising source of antitumor, antiinflammatory, and antiallergy agents.