The main objective of this study is to prepare activated carbon based on corn cobs with excellent adsorbent properties. To do this, a plan of experience was applied to 16 coals prepared with KOH and H3PO4 at different temperatures and concentrations. The plan of experience revealed that KOH, 1M carbon with a specific surface of 546.77 m2/g is the best. Experience has shown that H3PO4, 2M has a specific surface of 613.14 m2/g. The carbon activated by H3PO4 was characterized by determining the iodine number, the ash content, the surface functions, the pHzc and scanning electron microscopy (SEM). The results showed that activated carbon has a high iodine number (674.506 mg/g) and low ash content (6%). In addition, the carbon is acidic and has a porous surface.