Abstract: The dosage of microelements is the majority in MS medium. If changing the concentration of macroelements' combination can get more and stronger test-tube potatoes, this is beneficial to produce. Selecting the strain of potato 97-1-1 as the original material, MS＋5mg/L B9＋8％sugar＋0.4 mg/L IBA as the basic growth medium, through the way of changing multiple of numerous element concentration, the integral multiple of N, P and K concentration, separate multiple of N, P and K(orthogonal design) concentration in the inducing medium, we could get an optimum combination of numerous element. The result shows, when doubling N, P, K integrally and keeping other concentration of numerous elements unchanged, we can get the optimum combination of economic benefit. Without P and keeping other concentration unchanged, we can get the optimum combination of quantity of test-tube potato. Doubling P, K without N and keeping other concentration unchanged, we can get the optimum combination of diameter of test-tube potato.