Botryococus braunii BOT-22 produces hydrocarbon that is secreted naturally and accumulates in the colony of the strain. To avoid the high energy input and cost of the conventional thermal-drying of algal biomass before hydrocarbon is extracted with organic solvent, a new wet-extraction system was developed to control colony disruption and to recover hydrocarbon effectively. Culture media (biomass slurry) were passed through a capillary nozzle to disrupt algal colonies, then hydrocarbon was rapidly extracted with n-heptane. Quantitative analysis of the extract by gas chromatography showed that hydrocarbon was more effectively extracted at higher flow rate of biomass slurry. From the available experimental data, a dimensionless parameter of Reynolds number could dominate the extraction efficiency.