Abstract: The objective of this paper was to prepare fowl cholera microencapsulated vaccine with ethylcellulose.The fowl cholera microencapsulated vaccine was prepared by an emulsionsolvent diffusion method and studied the conformation，particle size distribution，imbedding ratio and the sustained release behavior.The particle size distribution was found within the range of 10 μm and 80 μm，the imbedding ratio was over 70％，the accumulated release rate was 39.72% in 72 h.The microcapsules made by the method are regular in its morphology，the reappearance of pharmaceutical technology was good，the process for the production of microcapsules was simple and facile，the in vitro release experiment proved that sustained release behavior was remarkable.

Key words: fowl cholera; microencapsulated vaccine; emulsionsolvent diffusion method; ethylcellulose