The expansion rate of single Shockley-type stacking faults was examined under ultraviolet illumination according to various basal plane dislocation structures with 90º or 30º Si-core partial dislocations. An attempt was made to explain the difference in expansion rate of 30º Si-core partial dislocations according to whether the basal plane dislocation structure was accompanied by unexpandable C-core partial dislocations. Moreover, the expansion rate of 90º Si-core partial dislocations was obtained experimentally and compared with that of 30º partial dislocations.