Cadaver preserved in formalin may develop pigmentation in the epidermis astime goes on.What is the nature of the colour substance?Are they degradationproduct of hemoglobin,melanin-like substance or others?In this paper,we reportthe results of observation on the pigmented substance from cadaver skin and charac-terize it by chemical and physical means.The epidermal layer of pigmented skin of cadaver was hydrolyzed by aceticacid,the hydrolysate was extracted with water and organic solvent in steps,thusthree portions were obtained:acidic water soluble,organic solvent soluble and inso-luble black precipitate.The later was identified as melanin by infrared spectrumanalysis,and chromatographic behavior after alkali fuse.The pigmented substancein acidic water and organic solvent are not identified yet.We also tried to find out the degradation products of hemoglobin,but wecouldn't detect them either by spectrum analysis or by crystallization of haem chlo-ride derivative.Hence,we intend that the deep colour of the cadaver skin after formalintreatment might be closely related to melanin,the mechanism of its formation isdiscussed.