In the developing world, the cancer as a prevalent cause of mortality is a new emerging challenges in medical and pharmaceutical sciences. Marine environs are regarded as a rich source of natural products with broad of therapeutic uses. Numerous BIOACTIVE PEPTIDES and depsi-PEPTIDES have been extracted from various marine organisms such as tunicates, sponges, molluscs and other marine organisms, with anti-cancer potential. They can produce the complex compounds which are more effective than presented anti-cancer drugs. Some of these marine PEPTIDES are under different clinical trials phases; they are secondary metabolites that produced by these organisms. According to different studies, their anti-cancer potential is related to some properties like antioxidant, anti- proliferative and anti-mutations effects. These PEPTIDES can stimulate cell death by various mechanisms, such as apoptosis, affecting the balance tubulin- microtubules (antimicrotubules), inhibition of angiogenesis, antiproliferative and cytotoxicity effects. Further studies on the reaction states of these compounds on cell cycle or apoptosis in cancer cells, are essential. The future of remedies, belong to the sea; and the sea, will have the major percentage in drug discovery, particularly in anti-cancer drugs.