To provide a two-cycle gasoline engine superior in scavenging efficiency, superior in a fuel consumption rate, and causing little environmental pollution by preventing mixing of exhaust gas of an air-fuel mixture at scavenging time.

This cylinder injection two-cycle gasoline engine has an exhaust means for exhausting combustion gas in a cylinder 1, a supercharging means 4 for scavenging by feeding preload air in the cylinder 1, a fuel injection means 11 for generating the air-fuel mixture by directly atomizing and injecting gasoline in the cylinder 1, and an ignition means 9 for burning the air-fuel mixture in the cylinder 1. Because of scavenging by a large quantity of costless air, the scavenging efficiency and the fuel consumption rate are improved, and the environmental pollution is reduced to thereby provide a lightweight high output gasoline engine for reducing a part while conquering the largest defect of a two-cycle engine.