Abstract: We present hereby the C₃₇ long chain alkenones record from the Core MD 05-2904 located in the northern South China Sea. The C₃₇ alkenones was applied to assess the haptophytes productivity variations. The content and Mass Accumulation Rates (MARs) of the C₃₇ alkenones indicate that during the last 260 ka, the productivity of the haptophytes has generally followed a glacial/interglacial pattern with high values in glacials, and low values in interglacials. And three high productivity intervals are identified in MIS 2, 4 and MIS 6. There were precession signals in both records. All these display a close link between East Asian winter monsoon and paleo-productivity, and on the orbital scale, marine productivity was controlled by insolation and monsoon variations, mainly through nutrients mechanism. And for the northern SCS, sea level changes and river transportation may also play an important role. These results are consistent with other reports. We also notice that, with consideration of both contents and MARs of biomarker, we can better decipher biomarker record, especially for those areas with big fluctuations in sedimentation rates.