Polyamide microcapsules were prepared by interfacial polymerization of 1,6-hexamethylene diamine with various acid chlorides such as sebacoyl chloride, terephthaloyl chloride and succinyl chloride. The chemical structures of polyamide microcapsules were identified with differential scanning calorimetry (DSC). The shape of microcapsules was an irregular sphere and the mean diameters of the particles were in the range of 0.5 ${mu}{ extrm}{m}$ to 2 ${mu}{ extrm}{m}$. The particle size of the microcapsules decreased with increasing dispersing speed in emulsification process. The results of DSC and thermogravimetry (TGA) analyses on the microcapsules indicate that the amount of core material is inversely proportional to the dispersing speed in emulsification process.