Abstract: With the help of scanning electron microscope,the morphological structure of the down was observed.Its unique divaricate structure and superficial structure were studied and a detailed description and characterization of the down were given.The difference between goose down and duck down and the difference between wool and down were compared.Their difference in morphological structure as well as the resultant difference in property were elucidated.This study fills the vacancy left by domestic and oversea researchers in characterization of down morphological structure and lays a foundation for further research in this respect.