An investigation was made of the characteristics of a corona discharge in He—Xe—HCl mixtures (close in composition to the active media of XeCl* lasers) at pressures of 100–300 kPa. Studies were made of the ignition regimes and of the characteristics of a corona discharge used in the systems for preionisation of the active media of excimer lasers and of selective high-pressure excimer lamps. A study was also made of the influence of λ = 337.1 nm laser radiation on the average current—voltage characteristics of a corona discharge in an He—Xe—HCl mixture. The conditions were found for the formation of a stable negative corona, which could be used for electrical circulation of active media of pulse-periodic XeCl* lasers, and also in preionisation systems of atomic Xe* and long-pulse XeCl* lasers.