An in situ observation instrument is dedicated to visualize and record the whole growth process of oxide crystal in low temperature organic melt and high temperature inorganic solution. Model experiments using transparent liquids such as salol, Li₂B₄O₇+KnbO₃ were chosen to investigate effects of growth Kinetics and interfacial transport phenomena. The growth rates of salol crystals in the super cooling range from 0⁰C to 3⁰C have been studied for (102), (012) and (112) faces. The transition from a lateral (two-dimensional nucleation growth) to continuous growth has been obtained by increasing the supercooling. For scaling of coupled velocity, heat and concentration transition in KnbO₃crystal growth, the widths of interfacial concentration, heat and momentum transition regions are obtained. The influence of the convection on growth kinetics and polyhedral instability of KnbO₃ crystal has been studied. The effect of buoyancy convection is to enhance the sharpness of interface and the influence of fluid effect can also enhance the morphological stability. These results agree with the DMSI (Diffuseness of the Melt-Solid Interface) theoretical calculation. A theoretical model of interfacial mass convection cell is also accounted. A pivotal feature in this model is the initiation of the surface tension convection on the interface of KnbO₃ grain. Direct comparison of the model predictions and experimental observed phenomena demonstrate the predictive capability of this model. The results show in situ observation method provides numerous experimental model for study of crystal growth.