In order to explore the characteristics of Mon-Khmer unidentified ethic groups, 412 individuals (220 males and 192 females) of which from Yunan province were selected as subjects for this study. By employing the anthropomorphic method, a total number of 58 features of head, facial and body parts as well as 20 specific physical indexes were measured and analyzed. Eight indicators were selected to be compared with those from 30 reported populations, including the head length, head breadth, face breadth, morphological facial height, stature, sitting height, shoulder breadth, and cresta iliaca breadth. The results from this research are shown as follows. First, most of the physical indexes of men were higher than those of women, except for the girth of thigh and 6 types of skinfold thickness. Meanwhile, the stature of both men and women subjects were considered as the short-type. Second, the percentage of upper eyelid eyefold of the tested males was 88.2% and that index of the females was 94.3%, with the frequency of the Mongoloid fold as 41.8% (male) and 36.5% (female). Nasal root height in this tested group was defined as medium for males and low for females. Ear lobe types of males were mostly round and those of females were basically with a triangular shape. Third, based on the index analysis, males and females were classified as the brachycephaly, hypsicephalic and tapeinocephalic type for head, leptorrhiny for nose, mesatiskelic type for leg, and with medium chest circumference as well as broad shoulder breadth. Besides, Cluster and principal component analysis indicated that the Mon-Khmer unidentified ethic groups were relatively close to those of Blang, Jino, Buyei and Dong ethic groups. Genetic factors, environmental conditions and eating habits are the reasons for the similar physical characteristics of these ethnic groups.