An ultrasound diagnosis apparatus (100, 300) comprising: a display (121, 140, 145, 340); a memory storing one or more instructions; and at least one processor configured to execute the stored one or more instructions to: acquire three-dimensional ultrasound volume data regarding a region of interest of an object (10, 501, 601, 701, 801, 1001); identify a plurality of two-dimensional cross-sectsions (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017), each including at least one feature to be observed, based on the 3D ultrasound volume data; determine priority levels of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017) based on the at least one feature included in each of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017); and control the display (121, 140, 145, 340) to display a plurality of 2D ultrasound images respectively corresponding to at least some of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017) based on the priority levels, wherein the at least one processor is further configured to execute the stored one of more instructions to acquire an area and a number of portions including the at least one feature in each of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017) and determine the priority levels of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017) based on at least one of the area and the number. a display (121, 140, 145, 340); a memory storing one or more instructions; and at least one processor configured to execute the stored one or more instructions to: acquire three-dimensional ultrasound volume data regarding a region of interest of an object (10, 501, 601, 701, 801, 1001); identify a plurality of two-dimensional cross-sectsions (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017), each including at least one feature to be observed, based on the 3D ultrasound volume data; determine priority levels of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017) based on the at least one feature included in each of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017); and control the display (121, 140, 145, 340) to display a plurality of 2D ultrasound images respectively corresponding to at least some of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017) based on the priority levels, wherein the at least one processor is further configured to execute the stored one of more instructions to acquire an area and a number of portions including the at least one feature in each of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017) and determine the priority levels of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017) based on at least one of the area and the number. acquire three-dimensional ultrasound volume data regarding a region of interest of an object (10, 501, 601, 701, 801, 1001); identify a plurality of two-dimensional cross-sectsions (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017), each including at least one feature to be observed, based on the 3D ultrasound volume data; determine priority levels of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017) based on the at least one feature included in each of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017); and control the display (121, 140, 145, 340) to display a plurality of 2D ultrasound images respectively corresponding to at least some of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017) based on the priority levels, wherein the at least one processor is further configured to execute the stored one of more instructions to acquire an area and a number of portions including the at least one feature in each of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017) and determine the priority levels of the plurality of 2D cross-sections (611, 621, 631, 711, 721, 731, 810, 811, 813, 815, 817, 1011, 1013, 1015, 1017) based on at least one of the area and the number.