Soybean agglutinin (SBA) was used to identify the location of N-acetylgalactosaminyl glycoconjugates in human dorsal root ganglia (DRG) and spinal cord. SBA bound to a subpopulation of small-diameter neurons in DRG and their central projections. It also bound to microglia and vascular endothelium. Vascular endothelium, DRG neurons and microglia do not originate from the neural tube, but penetrate into the neural tube in the embryonic stage and thereafter are located in the spinal cord. SBA binding glycoconjugates may be responsible for cell-cell interaction between these three cell types and tissues in human spinal cord.