The present invention relates to a window treatment mounting assembly, and a kit which includes a window treatment mounting assembly and a window treatment or modular fabric components thereof. In one preferred aspect, a window treatment mounting assembly for mounting a window treatment over a window is provided, where the mounting assembly comprises a longitudinally elongated channel beam for releasably retaining the window treatment; a resiliently compressible retention member for releasably coupling the window treatment to the channel beam in a friction fit; and at least one mounting bracket for supporting the channel beam in a mounting position adjacent the window.