Abstract: In this paper, a novel online palmprint identification method is presented, which includes the inscribed circle based segmentation, line feature extraction and bi directional line feature matching method Unlike the traditional rectangle based segmentation approach, a circle based positioning and segmentation method is proposed, which can deal with more palmprint distortions The bi directional matching method is to classify the lines into major and minor features first Then the two maps are matched in two directions and the matching scores are averaged By doing the bi directional matching, small noises and distortions that are introduced by palmprint capturing and crease extraction are compromised The experimental results verified the effectiveness of the proposed identification method