Aggregation is a typical behavior of Antarctic krill (Euphausia superba, thereafter krill). The distribution and type of aggregation is also the focus of krill behavior study. Based on acoustic data collected by Antarctic krill resource survey, the aggregation of krill around the South Orkney Islands from January to February 2018 was investigated using the Simrad EK60 (38 and 120 kHz) echosounder. The results indicated (1) a total of 3224 krill aggregations were detected, and the depth, length, thickness, area and density of krill aggregation were (218.52±455.66m), (11.19±13.98m), (1894.40±9345.72m2), (96.00±64.33m) and (114.11±159.60 ind/m3), respectively. (2) in different periods of a day, significant differences were found between depth, length, thickness and area of krill aggregations, but density of krill aggregation hadn’t significant different. In different depths of krill aggregation, there were significant differences between depth, length, area of krill aggregation, but no significant differences were found between thickness and area of krill aggregation, respectively. (3) three distinct types of krill aggregation were classified. Type I had the highest density (325.90±221.30m), smallest area (379.64±433.73m2) and deepest depth (158.06±67.54m); type II had the longest length (1089.60±1189.56m) and the area (15601.25±30243.33m2) were much larger than other two types; type Ⅲ had the lowest depth (78.91±52.88m) and smallest density (48.87±50.33 ind/m3), but it had the highest number of krill in the aggregation.