We inspected a distribution of events in spatial and temporal scales for two earthquake sequences of South Korea: the obtained spatiotemporal evolutions suggested a fault geometry in meter-scale without geological information and an expansion of hypocentral area without surface ruptures for the 2013 Boryeong offshore earthquake sequence and the 2016 Gyeongju earthquakes, respectively. The 2013 Boryeong offshore earthquake sequence was the consecutive occurrence of earthquakes (ML 1.3-3.8) over a two-month period in the Yellow Sea, west of the Korean Peninsula. The relocated 149 events formed a clear lineament in map view, which proceeded mainly toward NE without an obvious mainshock. The sequence, however, had a backward migration toward SW at first and produced the largest event that occurred after a pause of the sequence. We defined four event groups from the sequence using dendrogram for waveform similarity. The four event groups formed four distinct segments in spatial scale and showed its own features in temporal scale. The length of the second segment, 250 m, was comparable to the rupture length of the largest event (ML 3.8). The 2016 Gyeongju earthquake (ML 5.8), the largest instrumentally recorded event in South Korea, occurred at the southeastern part of the Korean Peninsula. We determined the expansion of the hypocentral zone from relocated 536 hypocenters during the first three months of the Gyeongju earthquake sequence. The foreshock zone covered depths of 13-15.3 km, with a length of 2 km in map view. The mainshock occurred 1 km south of the foreshock. The aftershocks, occurring within 12 hr, then widened the hypocentral area in the strike direction by ~1 km toward NNE and expanded it toward the surface. In this sequence, we observed that the strike of fault plane inferred from the hypocenter distribution was shifted slightly after the mainshock. The hypocentral area was finally stretched in the strike direction over ~1 km toward SSW by the largest aftershock (ML 4.5) that occurred 7 days after the mainshock and following events.