Self-biting is a chronic disease, which cause wound to take effect on mink growth and pelt quality. In this study, we firstly adopted RAPD (random amplification polymorphism DNA) technique based on the reproducible 26 polymorphism primers screened from 100 random primers to analyze hereditary constitution of the samples from healthy minks and self-biting minks, respectively, at molecular level to aim to discuss the causes of self-biting. The results showed that 29 straps showed polymorphism among amplified 105 straps, of which the polymorphism rate is 27.62%. Between healthy and sick mink groups, the amplified DNA fragment through different primers indicated different distribution frequency. The similarity coefficient of mink groups is 0.8471 and genetic distance (variation) index is 0.1529. Through primer S356 (whose sequence is CTGCTTAGGG), we amplified different straps between healthy and sick mink. The amplified 1000 bp DNA fragment in the sick mink groups can preliminarily serve as molecular genetic label to distinguish from healthy and sick mink groups to gradually remove the mink individual of self-biting, achieve to purify mink groups and reduce economy loss of mink breeding industry. This work provide theoretical basis for further study on molecular breeding and disease prevention of mink.