Objective To explore the law of changes in the appearance of Chinese Mongolians with age.   Methods Totally 24 human indexes of head and face from 4410 cases (1916 males and 2494 females) and 13 Mongolian ethnic groups were measured, and 12 craniofacial indexes were calculated. Correlation analysis was used to study the changes of craniofacial indexes and indexes with age. The method  of analysis of variance was used to study whether the differences between the index values and index values of the three age groups were statistically significant.   Results With the increase of age, the distance between the two mandibular angles became wider, the mouth widened, the width, height and length of the nose increased, the skin of the upper lip increased, the length and width of the ear increased, the width of the head, forehead, face, mastoid and tragus narrowed, the width of the eyes narrowed, the upper and lower lips thinned, the circumference of the head and the height of the head decreased, and the length of the head did not change significantly. With the increase of age, the Mongolian face becomes narrower and longer, the proportion of the height of the face in the whole head high school increases, the nose becomes wider, and the head appears to be relatively longer, lower and wider. The distance between the left and right frontotemporal points is relatively closer, the mouth cleft appears more slender, and the ratio of length to width of the ear does not change much.   Conclusion With the increase of age, the facial features of Mongolian have changed.