In this study, calcium alginate microsphere was prepared by an orifice method. The sodium alginate was used as wall material, and camphor essential oil mixed with polystyrene was used as core material, in order to investigate the optimal oil content and release properties. The parameters of concentration of wall material, the concentration of calcium chloride and the added amount of PS were discussed. The results indicated that microcapsulation the optimal oil content was 93.2% at the condition of 1% sodium alginate aqueous solution at the ratio of wall/core as 4:1, 2% of CaCl2. The camphor oil was released as near linear velocity at the conditions of 0.5% CaCl2, but became a closed type with CaCl2 over 1.0%. As PS content increased, the limit release time was better than pure camphor only. The limit release time was 737min as PS content was 10%.
