MHI G class gas turbine was designed to operate with a Turbine Inlet Temperature (TIT) of 1500 °C. This elevated temperature results in high thermal efficiency but also can induce relatively high emissions. MHI has developed a new Dry Low NOx (DLN) combustor that improves this class turbine compliance with stringent environmental regulations imposed around world. In addition to targeting an environmentally friendly combustor with lower emissions, the redesigned DLN combustor also improves the stability margin. Verification tests of the new DLN combustor were conducted in a M501G1 gas turbine at MHI’s T-Point Combined Cycle Power Plant from May, 2005 to March, 2007. In addition to verifying lower emission levels, these tests confirmed a wide stable operation margin as well as the reliability and durability of the components. The new design is optimized to be retrofitted into existing G class engines. The combustor is now in mass production as a MHI’s standard combustor. This paper describes the design process applied for the new combustor, including the Computational fluid Dynamics’ (CFD) and other analytical tools used.