With the help of thermodynamics and kinetics, the oxide metallurgy with respect to Ti treatment of low carbon steels is theoretically analysed. It is attempted to define and predict the optimal conditions for deoxidation of molten steel, which are decisive factors for controlling secondary inclusions, using the analysing method described below. The composition and growth of oxides during solidification are obtained by calculation featuring a good agreement with reported experimental results. But the present analysing model needs to be further modified in view of deoxidation kinetics.