Mathematical modeling of the rapid expansion of supercritical solution (nitrogen, nitrogenwater, propanemethanolphenanthrene) and formation of particles was performed. A 2D model of expanded supercritical fluid jet and unique calculation algorithms were developed and applied for the calculations. The calculations allowed determination of jet boundaries, shape, and position of normal and barrel shock waves, condensation front, and particles size distribution. Parameter sensitivity analysis of the model helped to identify which parameters are of key importance for the production of particles with the required size and properties.