The study investigated the basic theories concerning pictogram communication, including semiotics, cognitive psychology, communications, and design science, with literature review in order to explore the elements of pictogram messages, pictogram interpretation, the correlations between pictogram communication process and culture, and the correlations between pictogram design and trend; in addition, to provide a reference for laboratory researches on pictogram communication system construction. Results indicate that (1) a pictogram consists of a signifier and signified which translate the pictogram into meaning by means of identification, parallelization, deduction and inference; (2) the process of pictogram cognition is that eyes capture the feature of pictograms, transfer to the visual cortex by optic nerve for feature and structure matching, and comprehension; (3) the pictogram communication process includes pictogram encoding with shapes, colors and materials; media; receiver; and pictogram decoding, where cultural background is the pivotal key to communicate successfully; (4) "trend" becomes a central design concern as time goes by, and by applying universal design concepts, pictogram design can be made more tolerant. Additionally, the study via the discussion of above categories indicates that the 4 identification theories of cognitive psychology resemble what is emphasized in Gestalt psychology, and "prior knowledge" and "trace" in the field of cognitive psychology coincides with the "frame" and "redundancy" in the communications, and the idea that "all roads leads to Rome" is also true in academics.