Laser-assisted fragmentation of Au nanoparticles in liquid is examined experimentally by measurement of the size distribution function of particles at various moments of time. Theoretical approach based on the transfer equation is proposed to the description of the phenomena under consideration. Constructed mathematical model is implemented with parameters corresponding to the conditions of the experiment concerned. The results of simulation are in a good agreement with the experiment. (C) 2016 Elsevier B.V. All rights reserved.