Abstract: Experiments were conducted to investigate the effects of material strength and hole burden on the blast performance of fan-patterned holes in sublevel caving, and to analyze the factors affecting the effective area of blasting. Two important revelations were made in this study: (1) blasts with fan drilling exhibit a strong directionality, and (2) better fragmentation occurs in the hole-bottom region of the fan-patterned holes, where the hole spacing is larger, than in the collar region, where the spacing is smaller. The second phenomenon can be explained by the sequential effect of breakage, that is, between-hole breakage occurs first in the collar region where the spacing between holes is small. Based on the experiment results and conclusions drawn, the effective range of hole density coefficient and the application condition of hole-bottom detonation are discussed. The experimental results were applied to improve the load structure of charges and the sequence of detonation in Beiminghe iron mine. The percentage of oversized lumps of the blasted ore in the mine was lowered to 1.8% from 3.0% and the occurrence of partition wall was successfully eliminated.