Abstract:A systematical study of the types, height and width of wood rays of sixty-six species in nine genera in Magnoliaceae an China was carried out. The wood rays of major genera and species in the family are heterogeneous rays of type IlA and type IIB. The uniseriate rays are all low rays, the width of which is less than 0.05 mm and belongs to fine group. The multiseriate rays are medium and low rays, the width of which ranges from fine, medium to slightly wide. These characters indicate that Magnoliaceae is a quite primitive family, but it is more specialized than Tetracentron sinensis Oliv., Trochodendron analioides Sieb. et Zucc. and Winteraceae, which also have heterogeneous type I. In addition, these imply that subfam. Magno-lioideae is even more primitive than subfam. Liriodendroideae, and tribus Magnolieae is much primitive than tribus Nichelieae in subfam. Magnolioideae. However, the differences of wood rays are less distinctive in taxa of genera and below genera. Therefore, it is difficult to determine their systematic position merely according to the structure of wood rays.