The objective of this study was to use statistically based experimental designs for the optimization of xylanase production from Alternaria mali ND-16. Ten components in the medium were screened for nutritional requirements. Three nutritional components, including NH4Cl, urea, and MgSO4, were identified to significantly affect the xylanase production by using the Plackett-Burman experimental design. These three major components were subsequently optimized using the Doehlert experimental design. By using response surface methodology and canonical analysis, the optimal concentrations for xylanase production were: NH4Cl 11.34 g L-1, urea 1.26 g L-1, and MgSO4 0.98 g L-1. Under these optimal conditions, the xylanase activity from A. mali ND-16 reached 30.35 U mL(-1). Verification of the optimization showed that xylanase production of 31.26 U mL(-1) was achieved.