The tonsillar crypts show infiltration of lymphoid cells within the epithelium and the basement membranes of the crypt are highly porous or discontinuous. It is not clear when these findings occurred, so present study was designed to observe the prenatal and postnatal developments of the human tonsillar crypt epithelium. Tonsils of 4 fetuses, 4 neonates and 1 infant were obtained from autopsy and tonsils of 5 children and 4 adults were obtained from operation. 18 tonsils studied under immunohistochemical method using polyclonal anti-laminin antibody and monoclonal antitype IV collagen. 6 tonsils were studied under transmission electron microscopy. Epithelium of the tonsillar crypt from all fetuses and neonates showed infiltration of many lymphoid cells in H-E stain. The basement membranes of the crypt epithelium were intact and many small vessels were contact or just beneath the basement membrane of tonsillar crypt epithelium in immunohistochemistry. The basement membrane showed holes through which lymphocytes were passed in transmission electron microscopy. Tonsil from a 4 months old infant showed focal disruption of the basement membrane by immunohistochemical stain. The tonsils from children and adults showed that there were massive disruptions of the basement membrane and infiltration of lymphoid cells in tonsillar crypt epithelium under immunohistochemical stain and transmission electron microscopy.