Abstract: To investigate the relationship between fluctuating asymmetry (FA) of digit length and infertile men of the Han ethnic community from Ningxia, the mean values of fluctuating asymmetry (FA) of digits (2FA, 3FA, 4FA, 5FA) of 308 infertile men (primary sterility group totaled 196; secondary sterility group totaled 112) were studied. The relationship between 2FA and a+b ratio of sperm number were also analyzed, with the following results: 1) the primary sterility group had higher FA as compared to the secondary sterility group, with significant differences in 2FA (P<0.01), 4FA (P<0.05) and CFA (P<0.05); 2) the a+b ratio of sperm number was lower in the primary sterility group compared to the secondary sterility group (P<0.05); 3) there was a higher difference in the |L-R|≥0.04 on distribution of 2FA (P<0.05) and a significant negative relationship between 2FA and the a+b ratio of sperm number in the primary sterility group (P<0.001).

Key words: Infertility; Fluctuating asymmetry (FA); Digit length