An intrusion detection system( IDS) needs to deal with high-dimensional feature of data and it is easily overloaded. Meanwhile high-dimensional feature of data will lead to low detection speed and poor detection performance. To solve such defects,a novel feature selection method was proposed,combining the adaptive genetic algorithm( GA) with information gain( IG),In addition,a classifier based on support vector machine( SVM) is used for the calculation of the fitness function in the adaptive genetic algorit...