Human interaction becomes an important issue in the field of mobile robotics.To achieve human-friendly navigation,the robot needs to recognize human on cluttered backgrounds,and this can be fulfilled by the detection of human legs.The detection of human legs is advantageous because it enables detecting environmental obstacles at such heights.In this paper,we compared the performance of an algorithm using a single laser range finder(LRF) proposed in Ref.[1] with that of well-known feature extraction approaches- bounding box and circle fitting proposed in Ref.[2] by using the same laser scanned image.