Abstract: This paper reports on the trabeculae that are presented in tracheids and axial parenchyma of secondary xylem of 13 wood species. They are belonged to 8 genera and 4 families of Gymnospermae in China. The morphological characteristics and abnormal types of trabeculae in 13. wood species were observed and generalized 7 abnormal types with scanning electron microscopy. They are abnormal type 1— trabeculae with pantial thicked or sharp deficiency in wall deposition, abnormal type 2—discontinuous or break trabeculae, abnormal type 3—multiserial trabeculae in a series of cells or individual cell, abnormal type 4— trabeculae merged with radial wall, abnormal type 5—plank-like trabeculae, abnormal type 6—trabeculae appearing unevenly and not forming a horizontal row in cells, and abnormal type 7—branched trabeculae. Meanwhile, this paper has also discussed their origin and fine structure.