Investigating the historical development of the East Asian Monsoon was one of the primary goals of Ocean Drilling Program (ODP) Leg 184, South China Sea. An important component to achieving this objective is establishing an accurate biostratigraphic record of the basin. During Leg 184, one site was drilled in the southern South China Sea (Site 1143) and five sites were drilled in the northern part (Sites 1144-1148). This report presents the biostratigraphic analysis of 258 Miocene-age sediment samples recovered from Sites 1143 (112 samples) and 1146 (146 samples). The purpose of this biostratigraphy is to provide a planktonic foraminiferal age-depth model that improves upon what was created during the cruise (Wang, Prell, Blum, et al., 2000). Site 1143 is located at 9°21.72´N, 113°17.11´E (water depth = 2772 m), and Site 1146 is located at 19°27.40´N, 116°16.37´E (water depth = 2091 m) (Fig. F1). Both sites are within the influence of, and record the effects of, the East Asian monsoon. Site 1143 is also strongly affected by the seasonal fluctuations of the Western Pacific Warm Pool (e.g., McPhaden, 1993; Wang, 1999).