Deep convolutional neural networks (CNN) have demonstrated remarkable progress in stereo matching recently. However, disparity estimation in the ill-posed regions is still difficult. In addition, CNN based stereo matching methods often have impractical computational complexity and memory consumption. To address these problems we propose an end-to-end light weight CNN architecture to effectively learn and integrate low and high level information. To achieve this, a novel enhancement block built upon group convolution and dilated-convolution is proposed. Compared with state-of-the-art methods, the proposed method achieved competitive performance with the least number of network parameters on the Flyingthings3d and KITTI datasets.