The invention relates to a method for controlling a gas turbine group including, a first combustion chamber, a first turbine connected, a second combustion chamber, a second turbine, and a load. The method includes: measuring a temperature TAT1 at an outlet of the first turbine; determining a ratio S1R of a fuel mass flow feeding a pilot flame of the first combustion chamber to a total fuel mass flow feeding the first combustion chamber based upon the measured temperature TAT1 in accordance with a predetermined mapping table between ratio S1R and temperature TAT1; adopting the larger one between the determined ratio S1R and a predetermined booster ratio S1R to be used in the controlling fuel flow feeding the first combustion chamber of the gas turbine group. Pulsation behavior of the gas turbine group may be improved. High pulsation during fast de-loading of the gas turbine group is substantially is decreased, avoiding potential damage to the parts of the gas turbine group.