The pore in pastilles was investigated which are produced by a pastillation technology. Mercury intrusion porosimeter and scanning electron microscopy (SEM) techniques were used for the investigation. The formation of micro-pores and cracks were in dependence of the manufacturing conditions of the pastilles (final impacting velocity, degree of subcooling and surface roughness of cooled substrate). The total pore is decreased with decreasing degree of subcooling, final impacting velocity and surface roughness of the cooled substrate. In order to design a drug delivery system and to select an optimum manufacturing parameter the relationship between overall growth rate of the pastilles and total pore was experimentally investigated. The total pore increased with increasing the overall growth rate of pastilles.