Abstract: The paper reported a study on singlescrw extrusion of the composite sweet potato flour. The affecting factors on the product were analysed. The results showed that the degree of extrusion was closely interrelated with mois- ture and pH value of the sweet potato flour. The color of the product was better when the fresh sweet patato was soaked in the solution of 0.5% Na2SO3.And the dispersed nutrients of the product meant more rational proportioned while raw and processed materials were wade composite of 55% sweet potato flour,25% maize flour and 20% soybeen flour.

Key words: Sweet potato flour, Extrusion degree of expansion, Solubility