1. The data on the influence of temperature and rate of slip on the frictional action of elastomers confirms the results of Schallamach for compounds of natural rubber and indicates that the external friction of highly elastic materials is a molecular-kinetic process of transition of chains, which adhere to the other rubbing surface, over an energy barrier under the action of an external force and thermal motion. 2. The energy barrier, which is dependent on the force of adhesion of the rubbing materials (energy of activation), is changed only slightly by changing the temperature, load and crosslink density for compounds from the same rubber. A greater change in the activation energy occurs by going from one polymer to another (from 18 to 32 kcal/mole). It is higher for polar rubbers (SKN) than for nonpolar rubbers (NR, SKBM, SKS). 3. Independently of the nature of the rubbing pair, the friction of elastomers follows Formula (2) over the range of slip velocities of 0.001–10 mm/min. In spite of the use of extremely small slip velocities, such a limit was not reached which might be attributed to the existence of actual static friction with the highly elastic materials. On the contrary, the drop in the coefficient of friction with decreased rate of slip became sharper the smaller the rate. For all elastomers there is observered a drop in the force of friction up to 60–80°. Above this region is an anomolous portion of the curve, the more sharply expressed, the greater the polarity of the rubber. The anomolous change in the force of friction is connected with the increase in the effective area of contact resulting from the destruction of the secondary bonds in the three dimensional network and a decrease in the static modulus of the compound. 5. High modulus compounds give a linear relationship for the force of friction up to 100–120° while low modulus compounds have a deviation in their linearity which appears, the earlier, the lower the equilibrium modulus. The slope of the linear portion of these compounds is greater than that of the lower modulus compounds which is connected with the increase in the effective area of contact at the transition from a hard to a soft compound. 6. At small normal loads (to 3 kg/cm2) the properties of the law of friction may be described by Coulomb's law. The force of friction is a linear function of the effective area of contact.