Four dimensional response surface methodology was used to monitor the extraction conditions and predict the optimum extraction conditions on physicochemical properties of Liriope platyphylla. Maximum yield of total soluble solid was 66.02% into range of 35.06～65.70%, and maximum extraction conditions were 16.86 mL/g in ratio of solvent to sample, 99.55℃ in extraction temperature and 3.20 hr in extraction time. Maximum extraction conditions of total phenolics were 18.78 mL/g, 97.09℃ and 3.71 hr. Maximum content of crude saponin was 6.51% into range of 2.22～6.21 %, and maximum extraction conditions were 21.33 mL/g, 95.49℃ and 3.00 hr. Maximum content of reducing sugar was 6.75% into range of 2.43∼6.51%, and maximum extraction conditions were 22.93 mL/g, 89.64℃ and 3.75 hr. Electron donating ability was maximized in 16.74 mL/g, 99.63℃ and 3.16 hr. The range of optimum conditions gained by the superimposed four dimensional response surfaces on total soluble solid, crude saponin and reducing sugar of Liriope platyphylla was 15～23 mL/g, 92～100℃ and 2.4～5.0 hr. And total soluble solid, total phenolics, crude saponin, reducing sugar, browning color intensity and electron donating ability at the given conditions(20 mL/g, 100℃, 3 hr) within the range of optimum conditions were 65.75%, 1.30 mg/g, 6.33%, 5.93%, 0.11 and 10.52%, respectively.