Abstract: According to the feature of human head，this paper puts forward a method for recognizing human head based on the feature of contour.The method to clear burr of contour in threshold image，whose purpose is to prevent endless loop，is described in detail.One method to extract the contour is put forward，and the detailed steps are given out，too.Primary human head screening is carried on with the size of the area.Then the circularity is used to recognize human head.This method is not only real-time，but also needs less memory.At the end，experiment proves the good effect of the method.