The existing estimates on the primary productivity based on in situ measurements in the Yellow Sea show a large range of values from 11.78 to 2,694 ㎎ C m-2 d-1. Such high variability is remarkable considering that the Yellow Sea is a small shallow marginal sea and its circulation pattern is not complex. The large variability in the estimates reflects the highly variable environmental conditions such as turbidity and water column stability. The Yellow Sea is a good example demonstrating the difficulty of estimating primary productivity with a reasonable accuracy. The difficulty includes inaccurate retrieval of chlorophyll and light attenuation coefficient from satellite data. Photosynthetic parameters are also highly variable due to diverse light environment. Here we attempt to overcome some of these problems by dividing the Yellow Sea into two different regions in terms of light; turbid and stratified regions. The results and problems in such approach are discussed.