Seismic wave contain more information about the sediments. The seismic attributes has some relationship with the coal seam thickness. Through analysis of the wedge-shaped coal seam’s seismic attributes, when the seam thickness is less than the tuning thickness, there is proportional relationship between the amplitude value and seam thickness; while the apparent time difference between the wave peak and trough is not sensitive. When the coal seam thickness is above the tuning thickness, the conclusion is opposite. As a result, it’s difficult to predict the coal seam thickness only by using one single attribute. Therefore, we use the nonlinear-regression method to analyze the relationship between the seam thickness and both attributes, and get a method to predict the coal seam thickness. With the method we predict the coal seam thickness in a coal mine and get a perfect result.