The genetic algorithm (GA) is used to design vibration absorbers. The problem is formulated as mixed continuous and discrete variable problem. The continuous design variables include the mass, the spring constant and the damping coefficient of the vibration absorbers. The discrete variables are the installing locations of the absorbers. GA fits in this problem very well. Two examples are given. The near optimum solutions show that when the number of constrained frequency responses is less than or equal to the number of vibration absorbers, the optimum locations of the absorbers are exactly the nodes where the frequency response constraints are imposed. On the other hand, if the number of constrained frequency responses is greater than the number of absorbers, the optimum locations for the absorbers tend to be at the nodes that keep near equal distances to those constrained nodes.