To provide a method for preventing fraying of a surface of a paper web (namely, deterioration of surface strength) in paper-making processes by a paper machine, especially in pressing parts and drying parts, and to provide a release agent used in the method and capable of effectively preventing the fraying of the surface of the paper web.

This method for preventing the fraying of the surface of the paper web comprises applying the release agent T to members C which come in direct contact with the paper web W in the pressing parts P and/or the drying parts D of the paper machine, so that the deterioration of the surface strength which is caused by the fraying of the surface of the paper web W is prevented, when the paper web W is separated from the members C. The release agent is further applied to wire parts. Thus, the fraying of the surface of the paper web is prevented, and further the deterioration of the surface strength of the paper web is prevented, by suitably applying the release agent to the members (such as press rolls, drier rolls, canvases, and wires) which come in direct contact with the paper web in the pressing parts and the drying parts of the paper machine.