Abstract: Gasoline is a complex mixture of hydrocarbons composed by a variety of different monomer composition. Monomer hydrocarbon compositions of the main gasoline blending components in gasoline pool as well as alkylation gasoline alone are discussed. The octane number distribution of three gasoline blending components,i.e. S Zorb gasoline, reformate and alkylate, and the monomer hydrocarbons making a larger contribution to the octane number are also analyzed. The regularity of gasoline blending is analyzed in detail. It follows that the gasoline formulations with different monomer hydrocarbon composition can be made at the same octane number and total aromatic content. In addition, the gasoline with different boiling range can also be blended on the premise of equal vapor pressure.