In this study, calcium microspheres encapsulated eucalyptus essential oil was prepared by a orifice method. The parameters of optimal oil content, concentration of crosslinking agent, treated time, release properties etc. were investigated. The results indicated that the optimal of oil content was 91.8% at condition of 1% sodium alginate aqueous solution and 2% of crosslinking agent CaCl2. The alginate microspheres was became a closed type at conditions of ＞1.5% alginate or ＞2% CaCl2 or crosslinking time ＞20min. The limit release time of ruptured microcapsules were 326min, 516min under 9.80×104, 7.35×104, 4.90×104 dyne/cm2, respectively. The effect of sustained release was improved compared the oil released data with limit time 139min of pure oil without encapsulated wall material.
