To clarify the fate of glycosylphosphatidylinositol (GPI) in mammals, we developed GPI-anchored enhanced green fluorescent protein (EGFP-GPI) and transgenic mice carrying this fusion construct. When it was introduced to culture cells, the EGFP-GPI protein was correctly sorted to plasma membranes and microsomes depending on GPI biosynthesis. Transgenic mice carrying EGFP-GPI were found to show a broad transgene expression. Histologically, a prominent polarized localization of EGFP-GPI protein was observed in various epithelia, the nervous system and liver and secreted from some exocrine glands, as well as non-polarized presence in non-epithelial tissues, demonstrating a tissue-inherent manner of GPI sorting.