Damage to structures may occur as a result of normal operations, accidents, deterioration or severe natural events such as earthquakes and storms. Most often the extent and location of damage may be determined through visual inspection. However, in some cases this may not be feasible. The basic strategy applied in this study is to train the first three natural frequencies of the cracked cantilever beam in a genetic algorithm controller which works on the principle of evolution. Here Finite Element Analysis is used to model the crack. The result from the Genetic Controller has been compared with the Finite Element Analysis result. It has been found out that the results are in close agreement with each other.Index terms -vibration, natural frequency, genetic algorithm, fitness function, binary encoding, and genetic operator.