Objective To provide morphological basis for the cl application of maxillary sinus in Macaca Thibetana.   Methods Twelve lateral maxillary sinuses of 6Macaca Thibetana were dissected, and the position and morphology of maxillary sinuses, sinus cavity, orbit, nasal cavity and oral cavity were observed and measured.    Results The maxillary sinus of macaca Thibetana was located in the maxilla.The posterior sinus was located behind the anterior sinus and the sinus cavity was small.The anterior sinus was similar to the human maxillary sinus,which was located on the upper part of the first premolar to the second molar and the corresponding bone palate,adjacent to the orbit, nasal cavity and oral cavity. The sinus cavity and the interorbital bone were relatively thin, connected by the nasolacrimal duct,whose diameter and length were (4.3±0.10) mm and (15.89±0.31) mm. There were large constant holes in the maxillary sinus between the sinus cavity and the nasal cavity, with the length of the holes (12.59±0.46) mm and the height (1.01±0.12)mm in the natural state. The hiatal height increased to (11.14±1.44)mm when the cavernous vascular ball was pulled upward, The thickest bone between the sinus cavity and the oral cavity was above the root tip of the first premolar, and the thickness was (6.20±0.20)mm, the thinnest bone was ab   ove the root tip of the second molar, and the thickness was (1.57±0.23)mm,and the lowest sinus floor was between the first and second molars. There was not statistically significant difference between the two sides of the same individual.    Conclusion The morphological and structural characteristics of maxillary sinus of macaca Thibetana are suitable to be used as an animal model for the study of maxillary sinus lesions, maxillary sinus elevation and dental implant in humans, The maxillary hiatus is the best site for the non-fenestration approach to the maxillary sinus floor.