The morphology and kinetics of crystals growth in amorphous films of Cr2O3, ZrO2, and HfO2 have been studied by the methods of transmission electron microscopy (in situ) with video registration of structural changes. Based on the frame-by-frame analysis of the video the kinetic curves of the phase transformations have been constructed, which reveal typical features of the main crystallization modes: layer (Cr2O3), island (ZrO2), and dendrite (HfO2) polymorphous crystallization. For each mode the numerical values of the relative crystallization lengths (2036 for Cr2O3, 77 for ZrO2 and 4180 for HfO2) are determined. The crystal growth modes at electron-beam heating of amorphous films are compared with crystal growth modes on substrates at vapor condensation in vacuum (Frank-van der Merwe, Volmer-Weber and Stranski-Krastanov growth modes).