Biodiesel as a renewable fuel has much of public concern to reduce the human’s dependence on fossil fuels. A catalyst is necessary for increasing the rate of biodiesel production. The progress of biodiesel synthesisis focused on the efficiency of production and reductionof its negative impact to the environment. In this study, dolomite was used as a heterogeneous catalyst which was environmentally friendly inbiodiesel manufacturing. The mixed CaO.MgO oxide was resulted through the calcinations stage of dolomitemineral on optimum temperature (900⁰C). Before being applied as catalyst, mixed oxide was characterized by XRF, XRD, SEM and BET. The CaO.MgOoxidewas applied as a catalyst in trans-esterification reaction of palm oil and methanol to form biodiesel. The reaction yielded 78.09% biodiesel with 15% catalyst ratio to oil for 60 minutes reaction under temperature of 60⁰C. Dolomite can be used as a catalyst in the production of biodiesel from palm oil and methanol.