Abstract: To solve the segmentation problem of the blurred image edge and the connection of lung nodule to peripheral tissues, a new selection method is proposed by adaptive bandwidth mean shift and its mean shift is applied to nodule segmentation. Comparing it to the selection method by bandwidth on the basis of statistical analysis, it has the advantages of low complexity at time cost and getting correct bandwidth adaptive to actuality. According to the principle of bandwidth selection, the initial parameters of bandwidth are determined, and the most stable scale criterion of multi-scale filtering clustering theory was used to determine the optimal parameters of bandwidth. The proposed method was evaluated and tested for the clinical chest CT images including the nodules of different types, such as the ground glass opacity, the nodules lung walls and vessels adhesion, and anisotropic nodules. The results revealed that the proposed method is successful in segmentating lung nodules.