Separation of pure nasal secretions has been very difficult until now. Therefore, examinations were performed only with a small number of patients. Employing a new method to separate pure nasal secretions it is now possible to perform routine examinations. In this paper the protein composition and electrolyte patterns of normal human nasal secretion is reported. The amount of nasal secretion depends from the location and region of human nasal mucosa. The average amount is between 135 and 75 microliters. The protein concentration shows a very wide variation in the normal secretion between 200 and 3500 mg%. The average concentration in the upper nasal meatus is 950 mg%, in the lower nasal meatus 1100 mg%. Selective glycoprotein stainings show that the main part of nasal secret proteins are glycoproteins. The electrolyte concentrations were calculated for sodium 90-148 mval, potassium 6-28 mval and calcium 2-3.5 mval.