介绍了小波分析在层序划分中的应用现状，分析了GR曲线的小波变换在鄂尔多斯盆地延长组层序地层划分中的适用性。通过对GR曲线进行小波多尺度分解后可获得不同级次的旋回周期，将GR曲线小波旋回周期与传统标志层法、准层序分析法、古水深和基准面（湖平面）变化分析法和地震法标定的三级层序界面进行对照，结果表明，对正常湖相沉积，GR曲线D10小波与三级旋回较为吻合，可以作为延长组湖相层序划分的依据，而对冲积层序及浊积岩发育地区，D10小波容易出现偏差，不能作为层序划分的标准。

The current application of wavelet analysis in sequence stratigraphie subdivision was presented. The applicability of the wavelet conversion of gamma ray curve in the sequence stratigraphic subdivision of the Yanchang formation was analyzed. Different cycle orders can be obtained through wavelet analysis of GR curve. The comparison between the results of third order sequence stratigraphy obtained from wavelet analysis of GR curve, ordinary lithostratigraphy, parasequence analysis, analysis of paleo lake water depth and base level changes （lake level）, and seismic analysis shows that D10 wavelet of GR curve is consistent with third order cycle and can be used as a evidence of sequence stratigraphy analysis. As for alluvial and turbidite succession, however, the D10 wavelet analysis is not sensitive and can not be used as criteria of the sequence stratigraphy analysis.