Two kinds of fillers, such as carbon fibre and PTFE powder, were used for the present study of their effects on the friction etc. of polyacetal.The contents of those fillers are 5, 10 and 25%, and length of carbon fibre are 1, 3 and 5mm, respectively.The friction and wear tests were carried out by using the Suzuki type friction tester and Ito's sliding wear tester.The results obtained are as follows;(1) The kinetic frictional coefficient of polyacetal decreases with content of fillers, such as PTFE powder and carbon fibre.(2) The sliding wear amount of polyacetal containing PTFE powder is about 0.5∼0.7 times as much as that of unfilled polyacetal.(3) The value of limiting pv of polyacetal containing the fillers increases with the increase of the contents of both fillers, PTFE powder and carbon fibre, and with that of length of carbon fibre.The pv value of polyacetal containing PTFE powder is about 1.2∼2.2 times as much as that of unfilled polyacetal, and that containing carbon fibre is about 1.1∼1.6 times as much as that of unfilled polyacetal.