Monoamine oxidase A (MAOA), a mitochondrial outer membrane enzyme, degrades biogenic amines including norepinephrine, dopamine and serotonin, which have been implicated in the expression ofpersonality traits. We tested the associations between functional MAOA-uVNTR genetic variants and personality traits in a cohort of 370 healthy young Chinese females. Subjects who were homozygous for the 4-repeat allele of the MAOA-uVNTR gene tended to have a higher total score on the Harm Avoidance (HA) dimension of the Tridimensional Personality Questionnaire (TPQ) (p = 0.056), and had a significantly higher score on subdimension 4 of HA (p = 0.020) compared with the 3-repeat carriers. No significant association was demonstrated for MAOA-uVNTR polymorphism and the other two dimensions (Novelty Seeking and Reward Dependence) of TPQ. These results suggest that genetic variants of the MAOA gene may play a role in HA, but not in Novelty Seeking or Reward Dependence.