This paper introduces the structural design optimization of a tall building with reinforced concrete frame-core shear walls in Guangzhou downtown.To decrease the construction cost,wide flat beam with 400 mm ×650 mm rectangular cross-section are adopted for main beam.Special measures are used to decrease noncoincident centers of mass and stiffness.Because subway tunnels cross the building underground,inclined columns,the second and third floor underground together function as the underpinning structures.Different from traditional transform beam,the proposed underpinning structures show good performance without using large dimensional bending members.Special attentions should be paid to the beams connecting with the inclined column in the underpinning structures,and these beams show large tensile or compressive forces.Settlement observations after completion construction indicate that the building as well as the proposed design measures work well. This paper introduces the structural design optimization of a tall building with reinforced concrete frame-core shear walls in Guangzhou downtown. To decrease the construction cost, wide flat beam with 400 mm × 650 mm rectangular cross-sections are adopted for main beam. Special measures are used to decrease noncoincident centers of mass and stiffness.Because subway tunnels cross the building underground, inclined columns, the second and third floor underground together functions as the underpinning structures. Different from traditional transform beam, the proposed underpinning structures show good performance without using large dimensional bending members.Special attentions should be paid to the beams connecting with the inclined column in the underpinning structures, and beams show large tensile or compressive forces. Settlement observations after completion construction indicate that the building as well as the proposed design measures work well.