Objective To explore the effects of Rumex L. root extract on the morphology of tissues and organs in the mice of experimental psoriasis. Methods The experimental psoriasis model was established in BALB/c mice receiving commercially available imiquimod cream (5% IMQ) on the shaved back (dorsal) for 6 consecutive days. The drugs (positive controls and rumex L. root extract) were intragastrically administered at the volume of 0.2 mL/10 g. And then the effects of the positive control drugs (DXM, XYKL, MB) and the Rumex L. root extract (1, 2, 4 g/kg) on the morphology of the dorsal skin tissues, thymus, marrow and spleen, as well as the organ indexes of thymus and spleen were observed. Results Compared with the model group, epithelial thickening and parakeratosis of the mice in the 1 g/kg group were still visible. As for the mice in the 2 g/kg group, most epithelial returned to normal and there was also a visible area of epithe-lial thickening. As for the mice in the 4 g/kg group, most epithelial returned to normal and there were individual differences among the mice. Compared with the positive control groups (DXM, XYKL, MB), epithelial thickening and parakeratosis of the mice in the 1 g/kg group were still visible. In the 2 g/kg group, the changes of dorsal skin of the mice were similar to the XYKL and MB positive control groups. In the 4 g/kg group, the changes of dorsal skin of the mice were similar to the DXM positive control group. And there was no obvious abnormality of thymus, marrow and spleen morphology in the blank control group, the model group, the positive control groups and the Rumex L. root extract-treated groups (1, 2, 4 g/kg). Compared with the model group, the organ indexes of thymus and spleen were decreased in the DXM group (P< 0.01) and there was no significant difference in the XYKL group, the MB group and the Rumex L. root extract-treated groups (1, 2, 4 g/kg) (P> 0.05). Compared with the DXM positive control group, the organ indexes of thymus and spleen were increased in the Rumex L. root extract-treated groups (1, 2, 4 g/kg) (P< 0.01). Conclusions Rumex L. root extract can inhibit the IMQ-induced histological changes of mouse dorsal skin in a dose-dependent manner, but there are no obvious effects on the morphology of thymus, marrow and spleen.