Laser Induced Plasma Spectroscopy (LIPS) is a technique aiming at obtained mixture fraction inside practical combustor. The fundamental bases of the technique are first exposed and effects of pressure or blended fuels are discussed. A typical experimental setup is discussed as far as the application of LIPS to high-pressure is concerned. Some results obtained in combining LIPS and laser ignition are presented and discussed. Finally, strategies for global control are presented, in which plasma spectroscopy is becoming a sensor-actuator, quite unique and with several interesting possibilities.