A rate equation model is employed to investigate the surface dynamic processes such as In desorption, incorporation and segregation in the MBE growth of InGaAs and InGaN. In both cases, the agreement between our results and that of the experiment is good. In InGaAs growth, In desorption increases with increasing substrate temperature or group III-V over pressure ratio. The desorption process is observed to have two independent components, one arising from the physisorbed layer of In and the other from the surface of the crystal with activation energies of 0.18 and 2.6 eV, respectively. In InGaN MBE growth studies, In segregation is found to be negligible below 580degreesC. Above 640degreesC, the segregation dominates the surface kinetics. This temperature dependence is found to be independent of the fluxes. Activation energy for In segregation is found to be 2.9 eV. (C) 2002 Elsevier Science B.V. All rights reserved.