Abstract: Simplex method is a kind of mathematical optimum seeking method. It has been used to select optimum conditi ons of various experimental parameters.The author has applied the method to optimum seeking of experimental conditions for gas chromatography, such as flow rate of carrier gas, initial time, final column temperature, bridged eletric current, and the temperature of copper oxide oven.Through experiments and mathematical processes, five sets of conditions, i.e.Nos 12, 13, 15, 16, 17 points are considered to be the best. The basic idea of simplex method is to replace a worst point with a better one for the abrupt turn of a function.Thus, no matter how many dimensions a variable may has, only one experiment is needed for pushing one step to another.Besides, conditions selected by simplex method are gradually approaching optimum, and finally the graph will be oscilated within a certain range, which is the stable area near optimum conditions. So that multiple sets of conditions close to the optimum point can be chosen, and they are selective under different requirement.s Furthermore,because optimum point selected by simplex mehthod is obtained through comparision between experiments, there is no need for extra testing experiment.All these can not be achieved by other optimization method.