The Upper Carboniferous Huanglong Formation is generally up 0~30m in residual thickness in Jiangnan area, the eastern part of Sichuan Basin. Dolostone, limestone and breccia are common in Huanglong Formation, among which the formers are of better reservoir property. The dolostone comprises the most important reservoir in Carboniferous strata. Pinhole dolostone is of the best reservoir property in the dolostone reservoir while brecciated limestone is good in limestone reservoir. Based on the attribute quantitative analysis, wave impedance inversion and thickness prediction from 3-D seismic data, it is indicated that the Upper Carboniferous Huanglong reservoir rock is characterized by higher impedance than its wall rock. In the Huanglong reservoir, the pinhole dolostone is characterized by low impedance under the background of high impedance while the breccia dolostone shows high impedance. The analysis of log and seismic response characteristics of the reservoir has shown that Huanglong Formation is present when the double strong phase occurs in seismic profiles while Huanglong Formation is not present when the single strong phase occurs, which indicates that seismic intensity is closely relative with the thickness of Huanglong Formation. The result of predicting reservoir thickness by seismic attributes and wave impedance inversion is well accorded with that by drilling.