A glass run channel mountable along a window frame and made of a thermoplastic elastomer includes a base portion, a pair of side wall portions extending from the base portion, and projections that engage the window frame. A non-slip portion made of material having a larger coefficient of friction with respect to the window frame than that of the thermoplastic elastomer is provided on a face of the base portion opposite to the window frame. The non-slip portion is less slidable on the window frame than the thermoplastic elastomer, and further less slidable due to an orthogonal load produced when the glass run channel is mounted and pressed. Therefore, the glass run channel is stably maintained at a predetermined position in the window frame even if a force is exerted by sliding the window pane repeatedly.