Computer optimization technique was applied to obtain the optimum formula of o/w type ointment vehicle containing sodium lauryl sulfate and 1-methyl-2-pyrrolidinone (MP). In order to determine the feasibility of optimizing a vehicle composition with the aid of computer, the amounts of sodium lauryl sulfate $(X_1)$, salicylic acid $(X_2)$, and MP $(X_3)$ were selected as the independent variables for the solubility and the absorption rates of salicylic acid (dependent variables). The experimental values of absorption rates agreed well with the calculation values obtained from the polynomial regression analysis, and the contour charts drawn by computer were useful in optimization process.