Abstract: Objective: With β- poly malic acid and Chitosan as the coating materials, complex coagulation method was chosen to encapsulate Nifedipine into microcapsules of uniform particle size. Methods: According to the pre-experiment the order and the amount of addition was defined through the Plackett- Burman ( PB) experimentals and related factors in the evaluation, screening the remarkable effect factors, and then the optimum preparative conditions were obtained from orthogonal design of experiment ( designed by Box- Behnken) .Conclusion: The optimized preparation of sustained-release fragrance conditions were: the concentration of β-poly malic acid was 1.0g /L, the concentration of chitosan was 0.5g /L, β-poly malic acid and chitosan solution volume ratio was 2 ∶ 1, the pH value of chitosan was 4.0, the concentration of Nifedipine solution was 1.0g /L, nifedipine added to 3.0mL, β-poly malic acid solution dropping acceleration was 10.0mL /h, the stirring speed was 600 r /min, the reaction time was 45 min, the microcapsules of average particle diameter was 525.6nm and the average dispersion coefficient was 0.186.