Lactobacillus casei YIT 9018 was microencapsulated within alginate or alginate/chitosan double membrane using an air atomizer. Microbiological analysis revealed that the viability of encapsulated L. casei in gastric juice, hydrogen peroxide, and pepsin was 2-3 log cycle higher than that of the nonencapsulated cell. However, the encapsulated cells did not show a signifciant increase in survival when subjected to in virto high acid and 0.6% bile salt condition. Alginate-encapsulated, alginate/chitosan-encapsulated, and nonencapsulated cells were stored at different temperatures eencapsulated cells showed similar stability at $4^{circ}C$. However, at $22^{circ}C$, the alginate/chitosan-encapsulted cell was the most stable.