It was found that MgO supported catalysts gave liquid hydrocarbons and CO(2) selectively, from palm oil and other vegetable oil at around 703 K. The hydrocarbon product was composed of paraffins and olefins, whose carbon number was C(3) and C(10)-C(20) hydrocarbons whose peak located at C(15). Chemical structure of the products was the mixture of straight chain and branched chain hydrocarbons. The fluid point of the product was about 253 K. Supported MgO promoted the di-carboxylation of triglyceride or free fatty acid. The products showed lower acid value and iodine value. The product was successfully used for the diesel engine. (C) 2010 Elsevier B. V. All rights reserved.