Abstract: Objective: To study the distribution of palmar main lines on 300 normal people belonging to the Bai Nationality, and to provide normal parameters for this feature in anthropology, medicine and genetics. Methods: The ink prints of fingerprints and palmar patterns were obtained with informed consent. Results: For main line A, type Ⅲis 96 %, type Ⅴis 2.17 %, and type Ⅰis 1.83 %. For main line B, type Ⅴis 93 %, and type Ⅶis 7 %. For main line C, type Ⅴis 44.5 % , type Ⅶis 40.67 %, type Ⅸis 11.67 %, and type O is 3.16 %. For main line D, type Ⅸis 47 % , type Ⅶis 46 %, and type Ⅺis 7 %. The main types of A.B. C. D main line formula are 35′5″7, 35′79 and 35″ 79 (76.67 %). Bilateral symmetry of the A.B. C. D main line formula is 39.67 % with the major type being 35′5″7 (15 %). The average value of MLI is 6125 ±1137 (SD), and MLIT is 22152 ±3100 (SD). Both of MLI and MLIT exhibit significant difference between the sexes( P < 0.05), but have no significant difference between left and right hands( P > 0.05). Exactly 3117 % individuals have no C triangle. Conclusions: The distribution of palmar main lines in Bai nationality peoples has common characteristics with other nationalities, but also reflects different characteristics.

Key words: Dermatoglyphics; Palmar patterns; Main lines; Bai nationality