This experiment was conducted to investigate antitumor and immunomodulatory effects of Artemisia capillaris extracts against Hepa-lc1c7 and Sarcoma 180 cancer cells. In in vivo experimental tests using 210 ICR mice, on the $28^{th}$ day and the $42^{nd}$ day, all animals in vehicle controled HP (Hepa-lclc7 tumor cell inoculated vehicle control) and SP (Sarcoma 180 tumor cell inoculated vehicle control) showed tumor cells in the liver and spleen based on the histopathology. However, the incidences and the percentages of regions occupied by tumor cells were dramatically and dose-dependently decreased by mACH (Artemisia capillaris methanol extracts) treatment on the histomorphometry. Although the exact mechanism of inhibition of the incidences of tumor cells in the parenchyma whether inhibition of metastasis or proliferation is unclear, mACH dramatically reduce the percentages of regions occupied by tumor cells in the liver and spleen apart from the inoculation sites of Hepa-lclc7 and Sarcoma 180. In addition, they also effectively inhibit the abnormal changes on the kidney detected in the present study. The results suggest that Artemisia capillaris methanol extracts have prominent antitumor effects on the cancer cell lines Hepa-lclc7 and Sarcoma 180 m mice.