The results of experiments performed in this section showed that the maximum average yield of inulinase was 21.058 U/gds, which occurred when experiment’s conditions were as follows: the initial pH 8.5, incubation temperature 30 ◦ C and the concentration of KH2 PO4 and Ca2+ were 0.8% and 6 mM, respectively added to 3 g of artichoke leaves (low cost solid substrate containing inulin) moistened with 15 ml buffer (0.1 M, Trismaleate pH 8.5). Also the other variables which not included in the Taguchi experimental design were included at the concentrations of, 1% glucose, 1% sucrose, 1% NH4 H2 PO4 and 5 mM Mg2+ which give maximum production with PlackettBurman design.