The interactions between DNA and histone are studied by using the molecular combing method. With this simple but effective method, λDNA molecules are stretched to a length of 26—28 μm, 16—17 times of their contour length (～162 μm). After DNA binding of histones, DNA molecules are condensed and the lengths of the stretched complexes become significantly shorter, with length distribution peak lying between 10—14 μm. The lengths of the stretched DNAhistone complexes are closely related to the histone concentration and the mixing ratio of DNA base pair and dye molecule.