Heterogniety was found in the lectin binding patterns in human nasal glands but not between glands of the same patient. The purpose of this study was to investigate the relationship between the lectin-binding patterns and ABO blood groups in human nasal mucosa. Histochemistry was done with blood group specific lectins (DBA, GSI-B₄, UEA-I) and non-specific lectins (SBA, PNA, WGA, RCA-I, Con-A) using indirect peroxidase method. Blood group specific substances were detected in nasal mucosa. DBA and UEA-I were blood group A and H specific, respectively. GSI-B₄ was not blood group B specific in human nasal mucosa. From above results, we should consider blood group specific substances, presence of secretor gene, and maturation of secretory granules in interpreting the result of lectin histochemistry in human nasal mucosa.