Abstract: This study was based on natto as main material. Single factor experiments were used to examine the influence of proportions of gelatin, arabic gum to coating wall, the ratio of the mixed wall materials and the ratio of the wall-cord materials on microencapsulation efficiency. Then the optimal process of natto microcapsules was optimized, and the stability of the microcapsules was analyzed.The results showed that the optimal process parameters were as follows: arabic gum of 5%, gelatin of 5%, the ratio of gelatin/arabic gum of 1∶ 3, the ratio of wall-cord materials of 10∶ 1.Under these conditions, the highest rate of microencapsulated was 93.91% ± 0.21%. The irregular surface and the porous and loose inner structure of microcapsules were observed by scanning electron microscopy ( SEM) .The microcapsules were more stable than the native nattokinase by the p H and temperature.It would lay the foundation for the development of new products of natto and nattokinase.