The expression of a new dehydration-related gene of Physcomitrella patens, GFDD4-I, was traced for its localization in the plant cells. This revelation is useful to predict the possible roles of the protein in plant tolerance to environmental stress. This gene was fused to gfp marker gene and transfected into the plant protoplasts. Under a confocal laser microscope, it was detected that the GFDD4-1 protein associated with the OFF started to generate at the cell periphery and developed more intensively inwards to cytoplasm, forming vesicles and cystemal structures or network. The protein might be membrane protein which may involve directly in membrane maintenance or cellular protection against stress conditions.