Abstract: The preparation of nano-TiO2 microcapsule by complex coacervation was studied in this paper. Nano-TiO2 was selected as the core material and the gelatin and Arabic gum was selected as coating materials. The average particle size, embedding rate, and particle size variance of microcapsules were used to evaluate the technology of preparation. The factors such as pH value, reaction temperature, content of wall materials and stirring speed, were investigated to obtain the most optimal preparation. The results showed that the optimal conditions were as follows: emulsifying 1 % of Arabic gum and 1 % of gelatin, reaction at pH 4.2, solidifying at 50℃, and stirring with a speed of 750 r?min-1. Under the above condition，microcapsules’ average particle size was 90.1μm , embedding rate was about 85% and particle size variance was 12.1.

Key words: nano-TiO2, microcapsule, gelatin, arabic gum