Mechanisms of wet abrasion for nitrile rubber (NBR), polytctrafluoroethylene (PTFE) and fluoropolymer alloy (F50-1) have been investigated. Specimens were held against a rotating steel disc. Both the specimen and the steel disc were immersed in an abrasive liquid of the type used for oil-well drilling. The abraded surfaces of samples were examined using scanning electron microcopy. It is concluded that wear occurs as a result of two different mechanisms: a local microteadng process and a general microlayering or nlicropolishing process. Wear rates of polymeric materials have been found to increase with increasing sand content of media and with decreasing sliding speed. Mostly, these rates of bear also increase with normal load. However. wear rates of F50-1 were found to be surprisingly insensitive to normal load at 100℃.