Biologically active compounds with different modes of action, such as, antiproliferative, antioxidant, antimicrotubule, have been isolated from marine sources, specifically microalgae, cyanobacteria and seaweed. The structural characteristics of these peptides include various unusual amino acid residues, which may be responsible for their properties. Moreover, protein hydrolysates formed by the enzymatic digestion of aquatic and marine by-products are an important source of bioactive peptides. Purified peptides from these sources have been shown to have antioxidant activity and cytotoxic effect on several human cancer cell lines such as HepG2, HeLa, AGS, and MCF-7. These characteristics imply that the use of peptides from marine sources has potential for the prevention and treatment of cancer, and that they might also be useful as molecular models in anticancer drug research.This review focuses about the anticancer activating of peptides were prepared from microalgae in detail.