Abstract: A dynamic model was established for particle growth by vapor heterogeneous condensation, with which the condensation growth of soluble and insoluble mixed particles was investigated using numerical simulation, so as to analyze the influences of operational parameters on the condensation growth. Results show that the higher the number fraction of soluble particles in the mixed PM_2.5 is, the smaller the number concentration peak size and the median size of the droplets will be after condensation growth, resulting in more dispersed distribution of the droplet size. The particle size distribution would be significantly changed after condensation growth when soluble particles are mixed into the insoluble PM_2.5. The smaller the particle size is, the closer the condensation growth rate of insoluble particles will be to that of soluble particles. When the particle size is greater than 0.3 μm in diameter, the growth rate and final diameter of a soluble particle would be much greater than those of an insoluble particle. The growth rate of the mixed PM_2.5 can be promoted by increasing the initial vapor saturation and gas temperature. With the rise of number concentration of PM_2.5, the number concentration peak size decreases after condensation, while the particle size distribution becomes less-dispersed.