A method for use in displaying an expression phenomenon in a living matter that are capable of displaying (printing), in a format directly appealing to the eyes or sense, information indicative of gene expression phenomena occurring with time to assist a researcher with easy elucidation of a gene network mechanism. It comprises memorizing means that memorizes an expression data in a cell unit or a site unit along a time axis; and processing means adapted to visualize and display a gene expression phenomenon on a display screen, and comprises the steps of displaying, as a three-dimensional image on a display screen, a shape of a living matter of a cell or site of which expression phenomenon is observed; setting a viewpoint on a three-dimensional space where the gene expression phenomenon in the shape of the living matter displayed is to be observed; and creating a three-dimensional image representing the expression phenomenon at the set viewpoint or at a fixed viewpoint, to display it in one color or multiple colors in various scales depending on a frequency of expression of a gene in the subject cell or site.