The interface structure of poly (ether-ether-ketone) (PEEK)/carbon fiber composite ani the crystal texture of the PEEK matrix have been studied by scanning electron microscopy (SEM) after the samples are properly etched by argon plasma. We find that ail of the PEEK's crystals are induced by nucleating carbon fiber and then they developed the transcry-stalline no matter whatever the samples are crystallized from the melt or from the rubbery state The detail of the oriented crystal growth of PEEK relative to the carbon fiber has been obser-ved by SEM. The results of this work show that the nucheation process of PEEK/carbon fi-ber composite is as follows: the first lamella is formed in carbon fiber surfeace in the way that the a crystallographic direction is parallcl to the radial direction of the carbon fiber

b direction to the tangent line of cross section of the carbon fiber

and c direction to the axis of the carbon fiber.