Hydrothermal liquefaction of microalgae biomass at various temperatures was studied. The products were analyzed by thermogravimetry, elemental analysis, and gas-chromatography-mass-spectromeny. It was concluded that the temperature affected the product yield and composition. The quantitative contents of the major components in the gasoline fraction of the produced bio-oil were determined. The main components in the gasoline fraction were aromatic hydrocarbons, alkanes, and cycloalkanes. The hydrothermal processing products also contained significant quantities of phenols, organic sulfides, and nitrogenous organic compounds that prevented their direct use as fuel components.