The nasal glands secrete mucus, which is important for the control of humidification and foreign material removal from the inspired air. Knowledge of the innervation of nasal glands is important to understand the mechanism by which nasal gland secretes mucus and adjusts itself to variable changes of internal and external environments. Information on the morphological detail might provide the important clues to the study of structural basis for the nervous control of secretion. To study the ultrastructure of nerve endings in the nasal glands, the mucosa of inferior turbinate from three guinea pigs were treated by 6-hydroxydopamine(6-OHDA), and those from guinea pigs not treated by 6-OHDA were used as a control group, and were examined under the transmission electron microscope. The results were as follows : 1) The nerve endings in nasal glands were mainly observed in the intercellular spaces formed between interdigitated cytoplasmic folds of glandular cells, and desmosomal structures as seen in the synaptic junction of central nervous system couldn't be found at the contact area of nerve endings and glandular cells. 2) In 6 -OHDA treated group, we observed three kinds of nerve endings containing small clear vesicles(SCVs), SCVs and large granular vesicles(LGVs), and small granular vesicles (SGVs). But in control group, we couldn't observe the nerve endings containing SGVs. 3) After treatment with 6-OHDA, the mean number of nerve endings per gland cell was 0.693 in nerve endings containing SCVs, 0.160 in nerve ending containing SCVs, and LGVs, and 0.087 in nerve endings containing SGVs. From the above results, it was concluded that the nerve endings suggesting cholinergic, adrenergic, and mixed cholinergic-peptidergic were observed in the nasal glands of guinea pig and the main innervation of nasal gland might be cholinergic.