A new coagulant for spilled oil with bentonite and CaCl2 and sawdust has been done in our lab. The experiment indicates that bentonite is a good coagulant, especilly accompany with CaCl2 and sawdust. The function of bentonite is coagulation, adsorption and emulsification. CaCl2 is a good coagulant-mate, and strengthen the coagulating function of bentonite. It can be used as the source of calcium ions, which can strongly adsorb on both bentonite and oil droplets, and is helpful for the coagulation between bentonite and oil droplets. Sawdust is also very important, its function is buoyant, bridge-made and adsorbent.