Rock fragmentation is one of the major concern in surface mining because of its strong influence on the efficiency and productivity of the mining operation. Although past researches show that the size of rock fragmentation can be controlled by optimizing blasting designs, the effects of blasting designs or prediction methods of the size of rock fragmentation have not yet been discussed enough yet. In addition, the research works only focused on the controll and prediction of means size of the rock fragmentation. However, they have not considered the uniformity of the rock fragmentation despite all the size of rock fragmentation sould be ideally same in terms of efficiency. Firing patttern including delay time is one of the blasting designs which can be easiliy altered and has low impact on the production. Therefore, the effect of firing pattern on both the size and uniformity of rock fragmentation was discussed in this study. The results showed that two directions of firing pattern had advantage in terms of both mean size and uniformity of rock fragmentation.