Research aims to understand the effect of the percentage a catalyst CaO in bio oil against the character of physical and chemical. The catalyst used made calcium oxidae (CaO). This research used a pyrolizer who as fixedbed by heating derived from heater. To biomass used are waste shells palm and plastic bag with a mixture of 50: 50 , then added a catalyst cao with the 0 % wt , 5 % wt , 10 % wt , 20 % wt and 30 % wt. Raw materials a mixture of shells palm , plastic and catalyst inserted into reactor pyrolysis, then heated at a constant temperature namely 500 ˚C. Liquid as the result of products were conducted the measurement of the density and quantity bio oil, testing acidity, calorific value and GCMS (Gas Chromatography Mass Spectroscopy). The result of the measurement of the density of produce a mixture of a catalyst CaO 30% have the density of the greatest namely 887,9 kg/m³, while in testing acidity the highest value was found in the mixture of CaO 0% is 3.6. In the test of calorific value the highest value was found in the mixture of CaO 0% is 43,80 MJ/kg. Then, in GCMS test the results obtained in mixture of CaO 0% has percentage of hydrocarbon compound 78.09% and 21.91% oxygenate compound, in the mixture of CaO 30% has hydrocarbon compounds of 76.49% and oxygenate compounds of 23.51%.