Abstract: Triplebasic propellant powders consist of nitrocellulose, nitroglycerin or an equivalently acting explosive oil and crystalline nitroguanidino, which are processed by mixing with one another and plasticizing the NC by means of a solvent, e.g. acetone, as well as by kneading the mixture and subsequent shaping to solid propellant powder bodies. In order to improve the thermal stability, particularly the cold embrittlement behaviour, at least one organic titanate from the group of monoalkoxy, chelate, quaternary, neoalkoxy, cycloheteroatom or coordinated titanates and/or at least one organic zirconate from the group of neoalkoxy zirconates is added to the propellant powder in a proportion of .ltoreq.2%, preferably .ltoreq.0.5%. This addition improves the chemical stability of the propellant powder.