A coupled sea ice-mixed layer-isopycnal model (OPYC, alias PIPE) was applied to simulate the circulation in the Southern Ocean. The model domain covered the Southern Ocean south of 24°S. The model was first spun up in a coarse resolution grid (2°longitude×1°latitude) for 40 years running; then was shifted in to a fine resolution grid (1°longitude×0.5°latitude with a focus in the Indian Sector and the Antarctic Marginal Sea) for additional 5 years running in order to create the detailed circulation pattern in the area of interest. The simulated annual averaged volume transport through Drake Passage was 145.3×106 m3/s and more similar to the observed result (134×106 m3/s) than FRAMS result (about 200×106 m3/s). The simulated results of circulation and sea ice also agreed with those of previous results. The meridional stream function and meridional transport obtained from the simulated results were used to study the meridional characteristics of the Antarctic Circumpolar Current (ACC).