Pyrolysis is a method of producing oils from the raw materials of biomass by decomposing the thermochemical of organic materials at a given temperature. Free variables used in this research include pyrolysis temperature and biomass composition. The temperature variation of pyrolysis consists of three ranges: 100 - 200; 200 - 300; and 300 - 350 ⁰C. Meanwhile, the composition of biomass consists of five combinations of waste rubber and coconut shells ranging from 0% coconut shell and 100% rubber wood to 80% coconut shell and 20% rubber shell. Physical characteristics of the analyzed bio-oil include volume, pH, density, viscosity, and GC-MS analysis to determined its chemical characteristics. Research results showed that the pyrolysis temperature and composition of the biomass affected the characteristics of the bio-oil. The results of GC-MS analysis on bio-oil at 300 - 350 ⁰C showed that bio-oil with a biomass composition of 80% coconut shells and 20% rubber wood yielded 50.19% phenol. The percentage of phenol is greater than that found in bio-oil with 20% coconut shells and 80% rubber wood, which is 18.78% phenol.