Purpose: Curcumin, a polyphenolic compound that obtained from the herb of Curcuma longa, has many anticancer effects. But, its effect is low due to poor water solubility. In order to improve its solubility and drug delivery, we have utilized a nano-curcumin. Methods: In vitro cytotoxicity and anti-tumor promoting effects of nanocurcumin and normal curcumin were investigated. Results revealed that nanocurcumin is able to inhibit the growth of two human cancer cell lines Hep-G2 and HCT116 with IC50 values of 5.68 and 6.53 µg ml−1, respectively,while free curcumin expresses the activity with IC50  values of 8.28 and 9.64µg ml−1. At the concentration of 40 µg ml−1. Nanocurcumin showed anti-tumor promoting effects in reducing tumor size by 59.8 % , while the percentages caused by curcumin was 41.4%, respectively.  Mice were treated with equal concentration of nanocurcumin and curcumin showed an improvement in the antioxidant and anti-inflammatory cytokines. The level of improment in EC bearing mice treated with curcumin was lower than that of cells treated with nano curcumin (P=0.001). Conclusion:Results are suggesting that Nano curcumin  can be more effective than free curcumin in inhibition of Elrich ascites carcinoma cell lines.