Abstract: Shortbread biscuits were baked using blended flour in which the wheat flour (WF) was partially substituted with kudzu starch (KS). The properties of the blended flour dough and the quality of the resultant shortbread biscuits were analyzed using a rapid viscosity analyzer, rheometer, colorimeter, and texture analyzer. The color variation, hardness, crispness, puerarin content, and overall sensory evaluation score were selected as comprehensive scoring indexes, and the indexes were standardized to calculate comprehensive scores. The analysis revealed that with the increase in the KS proportion, the puerarin content, final viscosity, and retrogradation values of the blended flour increased significantly (P<0.05), whereas the storage modulus (G′) and loss modulus (G′′) of the blended flour dough decreased progressively. KS-incorporated flour yielded shortbread biscuits with more accentuated and varied colors. The hardness and crispness of the biscuits initially diminished and then increased with rising KS proportions, with the minimum hardness achieved with 20%~30% KS and the maximum crispness attained at 40% KS. At a KS proportion of 20%, the overall sensory evaluation score peaked at an impressive 85.75 points. At a KS proportion of 30%, the overall score peaked at 67.08 points, corresponding to a puerarin content of 15.89 mg/kg in the biscuits. In summary, partially substituting WF with KS effectively improved the quality of shortbread biscuits, with the optimal substitution proportion being 30%. These experimental findings lay the groundwork for the development of KS-incorporated food products.