Abstract：The effects of diesel engine combustion chamber design have important influences on the formation and combustion processes of the gas mixture, and greatly affect the power capability, fuel economy, and emissions of the engines. In order to make the design of the diesel engine combustion chamber more systematic and rigorous, the concept of diesel engine combustion chamber systematic design was proposed, which was elaborated from five aspects of design experience, design parameters, design criteria, factor processing methods, and response analysis methods. Nine design methods of combustion chamber were classified through combining three factor processing methods and three response analysis methods. The design method consisting of the factor sampling design method and the second type of the response analysis method was selected to illustrate its application process due to its effectiveness and convenience. A four-valve-head direct-injection diesel engine was analyzed, and a transient in-cylinder flow model was established. Under the assumption of an approximately constant compression ratio, the impacts of four different ω - shape combustion chamber structures on gas flow motions in cylinder were compared and analyzed. These four combustion chambers were named type A, B, C and D with shrinkage ratios of 16.4%, 6.1%, 9.8%, and 9.8%, respectively. The design evaluation criteria were gas flow velocity and turbulence kinetic energy. The results showed that the geometrical structures of the combustion chambers had little influence on the in-cylinder gas flow motions during the intake stroke and the early stage of the compression stroke, while they exhibited significant impacts during the late stage of the compression stroke. The average squish velocity and reverse squish velocity of the Type C combustion chamber, which had a conical bottom shape, was greater than that of the Type D combustion chamber having a spherical bottom by 25.2% and 26.4% respectively during the crank angle interval from 20° before the top dead center (BTDC) to 20° after the top dead center (ATDC). The average turbulence kinetic energy of the Type A combustion chamber with a shrinkage ratio of 16.4% was greater than that of the Type D combustion chamber with a shrinkage ratio of 9.8% by 25.4% during the crank angle interval from 20° BTDC to 20° ATDC. Compared to the type A and D combustion chambers that had a elliptic bottom shape and a spherical bottom shape, respectively, the type B and C combustion chambers that had a 45° conical bottom shape exhibited stronger capabilities of maintaining turbulence kinetic energy and reverse squish intensity. The results in this paper can provide good guidance for the structural design and optimization of diesel engine combustion chamber