A kind of a turbulent combustion chamber has been investigated. This combustion system gives the good tradeoff characteristics of exhaust nitric oxides and fuel economy. Typical combustion characteristics with some changes of design parameters of combustion chamber were observed. To understand combustion mechanism in this particular combustion chamber, air motion in the chamber was visualized by “spark method”. Faster dissipation of large scale swirl flow induced by inlet port and an active small scale turbulent corner flow were observed. Conclusively small scale turbulence generated by combustion, chamber was estimated to be effective to cause faster combustion.