Abstract: Thin bed distribution detecting through application of seismic reservoir forecast technique is difficult in seismic exploration. Detection of thin bed distribution is affected by many factors and specific questions which should be solved by specific analysis. In this paper, Fb thin bed oil reservoir of Pinghu oilfield was taken as an example through using forward modeling and seismic instantaneous attributes to detect the distribution of thin bed. For Fb oil reservoir, the characteristics of seismic response of forward modeling was studied and compared with the actual reflection characteristics, and seismic instantaneous attributes was used to forecast the distribution of the thin bed. Based on this, sedimentary background and single well phase characteristics were combined with the abnormities of seismic instantaneous attributes, which indicates that Fb is a small river-delta sedimentary system and the distribution of sedimentary facies are obviously recognized. The forecast results are consistent with the actual drilling results, which is the basis for economic development of Fb.