Cancer is one of human fatal diseases. Drug development for cancer intervention has many limitations in applications and often associated with serious of side effects. Recent development of natural product based and therapeutically sound anti-cancer agents have gained popularity in the field of functional foods, in which a few have minimal toxicity toward the prevention and treatment of cancer. Their structures were elucidated because of spectroscopic evidence. The cytotoxicity activity of 70% ethanolic extract of Citrus rutaceae peels were tested against colon carcinoma (HCT), human hepatocellular liver carcinoma (HepG2), human breast carcinoma (MCF7) cell lines and mouse fibroblast cell line NHK as normal cells. This assay gave spot on structure Citrus rutaceae peels and derived extract have demonstrated potent efficacious properties against liver cancer due in large part to the rich content of phenolic compounds such as flavonoids and coumarine compounds that, present in citrus peels. This study summarizes the results of currently available data regarding the in vivo anti-cancer activity of citrus peel phenolic compounds and identifies opportunities for subsequent human clinical trials to assess preventive and therapeutic effects in the near future according to Beijing Academy of Food Sciences.