This study aims to produce liquid smoke that will be used as plant pesticide by means of pyrolysis of a mixture of two types of biomass, coconut shells (CS) and empty fruit bunches (EFB). The parameters used are the ratio of the mixture of the two materials and the pyrolyse temperature ranges from 300 to 500 o C. A reactor of 2 kg capacity with indirect heating is used for this study. Heat is obtained from LPG combustion using a burner. Feedstock used in the form of pieces of coconut shells aproximately 5 x 5 cm 2 and the EFB of 3-5 cm in length are first dried using sun energy until they reach a standard dryness. Three difference of feedstock mixture composed of CS and EFB based on mass ratio (Mr) of 25:75, 50:50, and 75:25 are used to know their effect on the liquid product yield. During the process, the smoke is passed through the cyclone to reduce tar content, and then flows into the condenser with a water cooling fluid. After the specified duration of pyrolysis is reached, the LPG is turned off and the furnace is left for cooling. After that, the pyrolysis products; the liquid smoke and the char are collected. The influence of operating parameters such as temperature, heating rate, process duration, and the feedstock mass ratio were considered associated with the quality of the liquid smoke.