Two materials (one is metal) under slight relative motion in a liquid medium are submitted to fretting corrosion. This chapter is dedicated on studying fretting corrosion of implants. After describing the most significant implants submitted to fretting, fretting corrosion is defined. Fretting corrosion is a particular mechanism of degradations; it highlights the key role of passive film, crevice corrosion, etc. For understanding the electrochemical effect of the fretting corrosion of metal, some investigations are presented at free corrosion potential and at applied potential in order to measure the specific current density. Moreover the role of proteins is investigated because they constitute the biological environment. Thus they play a significant role in the fretting corrosion processes. Finally results from Atomic Force Microscopy (AFM) show the particular debris, size about 100 nm. Problem about debris influence is discussed