Abstract: The morphological structure,blending structure and all grades fibrillar structure of the PVA SPF were studied. The cross section of the PVA SPF appears anomalous noncircular,the longitudinal surface of it is slick with some stripes and grooves. Different from other wet spinning fibers,the PVA SPF is not skin core structure and about 0 2 μm thick cuticular layer,so it is clearly all core structure. The soybean protein is dispersed phase which is distributed stochastic and even,and the polyeinyl alcohol is continuous phase in the whole blending structure. The content of the fiber's cuticular layer is polyeinyl alcohol. There are obvious macrofibril structure which diameter is about 1 μm.