This research studies the digital image stabilization technique for the In-Car videos which are acquired from a car camera. Firstly, the relationship is established between the lane-line positions in a camera coordinate and an image plane. Then an analysis is performed to reveal the positions of the lane-lines in In-Car videos. Next, a digital image stabilization method for car cameras is proposed based on lane-line matching. This method begins with extracting the lane-lines from an In-Car video. Then, feature triangles are constructed to estimate the global inter-frame motions of the input video and a series of compensating motion vectors are yielded by using Kalman filter based algorithm with the inter-frame motions. Finally, repositioning the frames of the input video, according to the compensating motion vectors, can produce a stabilized In-Car video. The proposed method is resistant to the scene changes of In-Car videos. The experimental results, both for the simulated In-Car videos and the real ones, have demonstrated that the proposed method can robustly reduce the effects of undesired car camera motions on In-Car videos.