To find a simple method to detect the collagens in human hypertrophic scars.The content and distribution of collagen in human hypertrophic scars were observed with both conventional light and polarization microscopy combined with image analysis of hypertrophic scar sections stained with picrosiriusred.Polarization microscopy revealed closely packed thick fibrils of type I collagen fibers that showed either red or yellow intense birefringence in the hypertropic tissue, whereas type III collagen fibers consisted mainly of green thin fibril with weak greenish birefringence. The hypertrophic scar, as indicated by image analysis, contained (73.95+/-3.22)% type I collagen and (21.13+/-3.57)% type III collagen.Polarization microscopy and sirius red staining is an ideal method in analyzing the distribution and arrangement of the collagen in hypertrophic scars.