To investigate the influence of temperature and humidity on skin friction property and to unveil the mechanism therein involved, a test of friction coefficient for four volunteers was carried out on a multi-specimen friction tester. The temperature and humidity of skin were measured with infrared temperature instrument and dermohygrometer. The results showed that the fluidity and ductility of skin were affected by the change of skin temperature. The skin temperature decreasing friction coefficient and the normal displacement decreased first, and then remained unchanged, deformation friction and adhesive friction being the major underlying mechanism. Humidity significantly affected the skin friction properties. The friction coefficient increased with the increasing of humidity. When skin humidity reached to 42% or so, the friction coefficient increased to 1.0 and higher. Meniscus effect was noted to be the major cause of moist skin surface with high friction coefficient.