The present investigation has been conducted in order to evaluate the friction and wear behaviors of polyaryl-ether-ether-ketone coated with a Si/GLC film sliding against 100Cr6 steel, Al2O3 and Si3N4 balls in a biological medium of simulated body fluid, using the ball-on-disk tribological tests. The test results show that the wear volume loss of the rubbing pairs is two orders of magnitude greater than that determined for the tribo-pairs in SBF lubrication, coefficient of friction decreases by 50% at least, as compared to that in dry conditions. The friction coefficient showed the same varied trend with Hertzian contact radius. The wear rate showed the inverse varied trend with the contact pressure. The interfacial tribochemically reacted with moisture available in SBF medium plays an effect role of the difference in the wearresistant and lubricating behavior. Furthermore, some indexes including hardness ratio of pair and film were employed to predict the wear behavior of GLC composite films sliding against different counterparts. The Si/GLC nanocomposite films would be a new kind of promising materials applied to artificial heart valves and stents.